That is sooo true, Ananda. It seems to be a common trait that we expect so much more of ourselves than we would of others in a similar situation.
A gratitude exercise is a good fix for this a few moments spent on the positive outlook. So is mindful breathing, observing those self critical thoughts as they come in without reacting to them, sorta looking at them with an amused objectivity. Like, 'Huh! Wouldja look at that thought there!'. Then, accept them, that they exist, and then return the mind's focus back to breathing. Another variation on this is to picture a burning candle located in your belly, lighting a dark place, giving warmth and comfort. Your breathing and focus protects this light, so you again observe those miserable self thoughts and put them down again, returning to nurture and protect your inner light.
It's just a mind exercise, but I believe it has the power to rewire our messed up brains in time. The goal is achieved not by being able to maintain that focus for X minutes at a time, but when the thought is accepted and released. That's where the benefit comes.
It is a gift you can give yourself, Ananda. It is a kindness. Best to you.