Why do I shut down when things go wrong?

Why is it that everytime even a minor inconvenience comes up I shut down? I physically feel like I can’t speak. I wanna cry but can’t let myself show that weakness. I can’t even physically explain what’s going on. My brain gets very upset at me and I get mad at myself. I get physically upset at myself then have the urge to be self destructive. Does anyone else deal with this? This is something I’ve dealt with for as long as I can remember. I deal with MAJOR self destructive habits. When I’m not okay nothing matters and I literally do not care in the slightest about anything.