All it takes is one person saying the wrong thing and I fly off the handle at them. I hate myself.

Don’t let what people say affect you.
We all make mistakes and say stupid things.
And some people say rude things or are bad because they suffer a lot, or have experienced  things 

It sounds like you’re dealing with a lot. You didn’t choose to be easily triggered, it’s just something that you have - a mental illness - that makes you feel this way. You can learn to cope better with triggers and strong emotions in therapy. It takes time, truly it’s a lifelong process, but you can get better.