So I’m having the hardest time lately and of course all of this is in my perspective. Basically my significant other’s mother is extremely invasive and has no sense of personal boundaries. She is so controlling to the point that she is doing it in our relationship which I really don’t appreciate. She is demanding constantly of our location and what we’re doing 24/7 and needs all details simple answers never are enough for her. My SO literally is so unbothered by her behavior since he grew up with her all his life BUT IT HONESTLY STRESSED ME OUT SO MUCH. 
I get extremely triggered by her behavior because it reminds me of an abusive ex I had that would always monitor me because once I mention having bpd he thought I was scum and would cheat on him without any reason... so the fact I’m in another situation like that makes me feel like I honestly just deserve to suffer at this point. I don’t know what to do because she does love me a lot and is so sweet at times. But these kinds of behavior are so bad that I just want to break up with my SO to avoid her... any advice is helpful..