If it's any help, 5020, it sounds like I"m maybe at the same stage you're at, myself. I'm not officially diagnosed, but I've had enough symptoms throughout my life that it was suggested to me that I might have BPD, and since I have no money to afford it or actually get a formal diagnosis, I will have to work on it all myself, as best I can. It scared me at first, but then I realized that that's why there are forums such as this one - so you don't have to feel alone through it, at least.
The way I've read someone describe it that I really liked is that it's like that little red cartoon devil, sitting on your shoulder, encouraging you to yell, or be mean, or turn on someone, or to give in to being triggered or agitated and act out in a nasty way until you're totally out of control. While you may not be able to completely get rid of that little devil, you can learn how to cage it and keep it from getting to you. I bet you'll be well on your way to doing that in no time!
There's a guy on YouTube I found recently who is really helpful to me. I don't know if you would respond to his way of doing things, but he does videos that are basically quick guides to helping you control emotions as soon as they start getting the better of you. I think links are forbidden on this forum, but if you were ever curious, his channel is called "Me And My Black Table." He's a real sweet guy who's been struggling with BPD, and doing very well! Just a small warning, he does address self harm as well in many of his videos, so if that would be at all disturbing to you, I wanted to make sure you knew before looking so you don't get triggered by that. He's a very positive and friendly guy, and you can really watch him blossom from being a timid, unsure guy to a really outgoing and positive presence! If he can do it, and Smile can do it, and many others on this forum who are recovered mods can do it - I know you can, too!