Reb Avrohom Alter Heber, after learning in Kfar Chabad for a few years, came to learn at the 770 Yeshiva in 5726. As a serious bochur, he was quite intense, and when he went into yechidus, he asked the Rebbe how to deal with his anxiety.
“This that you write about your strained nerves,” the Rebbe responded, “this is due to you making self-assessments too often, every day or every hour.
“This itself restrains you from actually doing things.”
“When the [Frierdiker] Rebbe spoke of cheshbon nefesh, he was referring to a few times a year, or a few time a month, or at special times. But not every hour...”
(Ovinu Roeinu p. 77)