Since I don’t know anything more than what you have written, it’s hard to know which personality disorders you’re referring to, or who decided upon the diagnosis. While I have no reason to doubt you, there are unfortunately many cases where a label is stuck on a person without genuine justification, which leads to a cascade of behaviors which only serve to exacerbate any problems that do exist.
There are different ways of understanding the nature of “disorders” and different theories regarding how they are best dealt with. Anyone can understand that labeling a person “crazy” is likely to bring out the worst in them, and also that distancing oneself from a “crazy” person is unlikely to be the best course of action if the person is only a mild variation from the norm. However, there certainly are situations where it’s extremely difficult to interact with such people and times when creating distance is truly and sadly the best approach.
Interacting with people with personality disorders can be extremely draining. Based on the scenario you describe, I’m glad that you have not fallen into the trap of taking responsibility for their behavior, as doing so is a common mistake and isn’t helpful. Unfortunately, there are well-meaning people who encourage the healthier family members to assume responsibility for their “poor, hurting relatives.” Regardless of how much someone is hurting, there is no excuse for unacceptable or abusive behavior, even if the narrative they tell is that they were “provoked.”
There is a middle ground between blaming oneself for an unwell person’s outbursts and becoming furious with them, and that is having rachmanus. A person who is so fully in the grip of his emotions that he is (or seems) incapable of logical, rational thought really is pitiable.
My personal belief is that many or even most personality disorders are the result of hypersensitivity gone haywire, where, for whatever reason, a person is so flooded with emotion at even the slightest provocation that they simply “lose it.” It's painful to live with or have to deal with such outbursts, but the “disordered” person is even more of a rachmanus because they are incapable of forming stable, loving relationships with anyone. Feeling pity for them helps to overcome resentment and anger and can make it easier to deal with them.
Unproductive Confrontation
Often, someone can be exhibiting such irrational behaviors that people are tempted or even encouraged to bring it to their attention and show them how ridiculously or unacceptably they’re behaving. This approach is never productive. People in the grips of such a disorder lack the awareness necessary to see themselves from the outside. It’s not unknown for such people to see their very issues in the people around them and to blame others (usually those closest to them) for being the “crazy one.” Even if they do recognize that what they’re doing is wrong, they will attribute it to the “fact” that they’re living with someone “crazy” (perhaps with the exact disorder they are dealing with), which is what makes them “react” the way they do.
One of the reasons why this can happen is that living or interacting with someone disordered is so stressful that it actually can cause others to behave in less-than-optimal ways. This is why even trained therapists are sometimes taken in by the manipulations and distortions of such an individual and end up blaming the other spouse for starting the downward spiral. Others cause as much damage not by blaming the victim, but by stressing how crazy their disordered spouse is and focusing on self-protection or even fighting back, which just makes things worse.
It’s very challenging to deal with someone so triggering, especially if you are being blamed for it, and it’s important to seek out the right help — help that actually helps, and provides solutions.
Setting Healthy Boundaries
Setting healthy boundaries will definitely be part of a solution. Every relationship depends on healthy boundaries, although they may not need to be intentionally and consciously enforced. However, with people who are emotionally unbalanced, setting and implementing boundaries is both difficult and vital, as otherwise, the healthier person can get sucked into the other person’s orbit.
It seems from your letter that you and your husband have already made an excellent start in establishing boundaries. While everyone wants to just “get along” and be nice, sadly this is not always possible. Part of getting along sometimes entails drawing red lines, in order to maintain one’s sanity.
One important thing to keep in mind is that the purpose of setting boundaries is not to create distance. On the contrary: boundaries are what enable us to connect, and this is what we all want to be able to do, in a healthy way. Therefore, it’s important for you to clarify to your relatives that you would very much like to be able to have an open, easygoing relationship, and yet you simply can’t hold a conversation with them if they start verbally abusing you or others, or making unreasonable demands, and so forth. Always stress how much “I love talking to you, and it’s only when you start saying nasty things about my husband/wife etc., that I feel the need to change the subject or end the conversation.”
Obviously, with your father-in-law, there is the added consideration of kibbud av va’eim and one has to be careful not to be disrespectful. It’s important to consult with a Daas Torah before setting boundaries, and not to decide how to do so on your own. In general, when you focus on how difficult it is for you to deal with a certain attitude or speech, rather than what they are doing wrong, you’re on the right track and can avoid ever being disrespectful.
Enforcing Boundaries
Boundaries have two aspects to them: establishing them and enforcing them. A boundary that isn’t enforced may as well not be there at all. It’s important to determine in advance the outcome that will always transpire if the red lines are crossed. Then, you have a discussion with your relatives, in a calm moment, during which you gently tell them the consequences they can expect if they refuse to respect your red lines.
You should make it clear that the consequences are not punishments, and that this is nothing to do with you being angry at their behavior. It’s a simple cause-and-effect, as you can no longer tolerate certain things that you are making known in advance.
The outcomes you decide on must be implemented regardless of how they decide to react. This might mean hanging up the phone, or not visiting. While you must be firm, you should also remain calm and avoid sounding disrespectful or confrontational.
Establishing boundaries means that you remain in control of your own life. Therefore, if a family member tells you that you are “not allowed to grow,” you simply ignore them, because it has nothing to do with them at all. As mentioned, it’s important to consult with a Daas Torah when it comes to parents, but generally speaking, one is not obligated to obey even a parent in such a case, as their child’s growth has no direct impact on their life.
It’s hard to get technical, but usually, if someone counters with “consequences” of their own, such as (as you describe) not talking to you for weeks on end for no good reason, as sad as it is, and as much as you want to be peaceful, it’s better to simply ignore their behavior and not attempt to placate them. Don’t address their “hurt feelings” — just continue to call them on the phone as if nothing happened. Don’t get sucked into other people’s version of reality, and don’t try to disprove their narrative, thereby giving it credibility as something that merits attention.
Appreciating Your Spouse's Choices
I understand that it is difficult to see your husband having to choose between his family of origin and his wife. Know that this can happen even in families where no one is “personality-disordered,” and appreciate what your husband is doing for you. Don’t take his devotion to you for granted. Too many marriages flounder because one of the spouses doesn’t want to make such a choice, or makes the wrong one. Although it’s far from the optimum outcome as far as you’re concerned, appreciate the choices he makes and thank him for them. Tell him how much it means to you that he stands up for you and won’t let his father or sisters bad-mouth you. Tell him how much you wish it wouldn’t be that way.
I cannot know from the few details you have provided, but it's actually possible that your sisters-in-law are jealous of your excellent shalom bayis. They may not even be aware of this themselves. But this is a dynamic I have seen, where people who are jealous of a good relationship between husband and wife actively set out to ruin things. Tragically, in some cases they succeed.
Baruch Hashem, you and your husband are making the right choices for the right reasons, and I hope you will find here support and encouragement for continuing in the right direction.