I definitely recognize this as something younger me was doing constantly. And I wouldn't listen to anyone who would tell me I'm actually a pretty good person. It would have interrupted my internal monologue of what a useless person I am.
Digging further I found that I was expecting sainthood of myself, so every little misstep (pecadillo) was evidence that I am the literal Spawn of Satan and was going to bring about the Damnation of All Mankind, but for the fact that I have no useful abilities.
So - what helped (this was under the guidance of a therapist though and I am just throwing it out there but not recommending you do anything unless you are ready) was to feel the feelings. Not label them, as in, sad, angry, etc, but feel the sensations in my body. Stop telling myself stories about why and what this means and feel my body in space without needing to change anything because I could see it was always changing anyway. In other words I would notice, for example, a tightness in my chest and throat - so I'd watch that, and it moved around to other parts of my body but it dissapated shortly, and was replaced by a new sensation. For some reason this seems to have helped. Having a greater awareness of what I call my "wetware" moment to moment seems to prepare my emotional state to see that I deserve compassion from myself as much as anyone else does (I think that was the Dalai Lama, but can't promise).
We are bodies as well as minds. For those of us that over-analyze and over-think, there is likely a reason, such as past trauma or abuse, that makes the body itself a place to be feared. In my case it led to me being so far up in my head that I couldn't even feel my feelings; I was entirely numb but still intellectually voracious. However, the body is happy to have us when we decide to tune in.