The Rambam says that only external and visible Mu’min (blemishes) are Passul (disqualified), like a broken foot or hand. But a Cohen with an internal Mum may do Avoda, even if he is a Treifa (terminally ill), Rachmana Litzlan! I knew a person who had been Nichshal in serious sins, and he used to talk openly about them. I told him to stop advertising his shortcomings and his sins.
Besides being a Chilul Hashem, it’s also a Shiflus to put yourself down; and it's a Yetzer Hara. Don't reveal your embarrassing secrets. R' Nosson Wachtfogel Zatzal was against saying certain things which were not meant for the public. (Therapists can be guilty of this. However, sometimes it is Davka appropriate, especially when there is a Tachlis - benefit).
So let the world think that you're a bigger Tzaddik than you really are; so what! I heard in the name of R' Avigdor Miller Zatzal that if someone knocks on your door, quickly open your Gemara so he'll think you're a Masmid! Always focus and talk about your positive side, and keep your 'garbage' in hiding, unless there is a Tachlis.
