Big hugs to you.

It's not dumb at all. What you described is something I go through a lot. What seems like a minor annoyance to "normal" people (if there really are any of those) can set off those of us with mental health issues in nothing flat. Happens to me quite a lot. And then the one thing kicks off another, and another, and you keep spiraling.....ah yes, I know it well.

I think people SI for different reasons. Control certainly is one. Perhaps there's the thought that if you hurt yourself, you can keep others from doing it to you. For myself, I tend to do it when I get angry at myself for not meeting my own expectations. Oftentimes too it is to have a physical manifestation of the emotional hurt.

It's OK to avoid people for now, I think. I'm in the middle of that myself right now. And while you'll hear a lot of advice to go out! do something! get outside of yourself!, it is damn hard, when you feel like this, and a little indulgence of it isn't a bad thing. If it goes on for months, then you probably should address it with a therapist.

Dunno if any of my ramblings helped, just wanted you to know you aren't alone and you aren't dumb.