Adhd person thinks that you're the one that has a problem and he is always right I

I  have been with my boyfriend for 18 yrs we have son 14 I knew for years my boyfriend had trust issues his previous wife cheated on him with his friend.  Which was nd still isiss  always being accused of doing something that I didn't do say cheating on him or whatever I never have then he say why you getting so defensive which made him think due to guilt no it s due too innonencee   constantly trying to defend myself the issue would resolve only when he was done with it angry person name calling short tempered outbursts and always wondering if you got his back and am  I loyal. He only mean to my self ad his mother. I never do anything for him.  No need to go into that BS he was just recently diagnosed at the age of 50 with ADHD  his issues stem upbringing due to stepfather not nice and mom taking dads side.  He even more a jerk (sorry)I'll do what I want and don't tell me what to do we haven't lived together iin 13 yrs last night was being accused of having a second phone line not the first time being accused of it and am doing conferencing calls so he would sometimes call me with a no caller ID trying to trick me and if I answered why did I answer  either of us being technical people so then I spent hours upon hours trying to prove to him that I did not have the second line and once again after all these 18 years never cheated it always comes back that I'm the one that starts an argument he does not communicate any time I try to express my feelings not now I give them a headache he's too tired but yet there have been times when he wants to talk about an issue that he blew out of proportion he showed up my house for o'clock in the morning and I live with my mother who is in her 80s and the issue he has is usually something that's not true and is trying to convince me of things that I said when I know I didn't so I usually agree with him to calm the situation so supposed to start this medicationand just started talk therapy so hopefully they'll get to relationships he's not nice to his mother either we are triggers he has three adult children if one of them were to say same thing to him  he would get tearful  because they care      if you get a chance listen to and check out the lyrics to Lincoln Park new song heavy it's a good song