Honestly I don't know what the answer is here. But I think it may (perhaps) be to talk to your parents & get back into some sort of therapy. You wrote you were so uncomfortable with your therapist you refused to go. Maybe that just was not the right therapist for you? It can take a while to find a therapist you feel comfortable with. Not every therapist works well with every client. Maybe try a different therapist... or a different type of therapy?

You wrote you went through some pretty traumatic stuff but you haven't opened up to anyone & you're scared you might do something you'll regret. Please don't! What I can tell you is that I'm an old person now. But many years ago I also experienced some traumatic stuff. And I never said anything about it to my parents. (It's a long story & I'll spare you the details.) But what happened to me has, to some extent, followed me down through the decades even to this day.

Please don't do that to yourself. Reach out in real life, in whatever way you feel you can, for the help you need. If you're in school, & you don't feel you can talk to your parents (I never could have), perhaps consider talking to a school counselor or a trusted teacher, if there is one. Posting here on PC can certainly be helpful too. But ultimately what you are really going to need, I would presume, is help & support in real life. I hope that, in some way, you will be able to find it.