First off, im on mobile so sorry for any formatting issues.

We have a family history of BPD on my dad's side and my whole childhood my dad refused to get help for it or even admit he had it because he didn't want to be like his father who had it and now I'm worried my sibling is doing the same thing. Right now I'm in the 'hated' category for my sibling and im starting to be legit afraid of him. Hes been flying into rages more and more often and he staunchly refuses to get any sort of help for it. Hes agreed to in the past but he always cancels the appointment the day of and then is just ANGRY. He VERY rarely hurts people in his rages before, never badly, and he's only done it in the past year. Usually just breaks stuff and tells people how much he hates them then goes to sulk for a bit, hes more of a danger to himself than others, but he has hit people and thrown things at them before and I dont feel its unreasonable to be scared. 

Its getting to the point where im scared to come home and im stressed all the time whenever im there and I truly don't know what to do. I'm planning on moving out but it won't be for another few months. I want to have a good relationship with him, hes my brother and I love him and when he's not angry he's a really great person to be around, but I've done this whole shtick with my dad before and I really don't know if I can do it again. I dont want to hurt him or set him off but im to the point that when I move out I want to just tell him I'm not going to talk to him unless he gets therapy. I feel like at this point its a reasonable thing but my mom is worried it'll just set him off. 

I truly don't know what to do. I love him and I want him to be ok but I also just can't take this anymore. I've tried being as understanding as I possibly can and give him as much space as he needs its just not getting better, its gotten much worse actually. I've struggled with my own mental health problems and this is making dealing with the SO MUCH harder. 

Should I try to talk to him about it or should I just stay out of his way for the next few months?? Its triggered his anger before if I try to talk to him about it. I really want him to be ok and I want to help him