Paranoia issues

Hi, I really need some help. I have been with my boyfriend for two years now, everything was going great but he started to get really obsessive and paranoid a year ago. Now things are so bad that he says I am lying to him and that he doesnt trust me. I am a very happy cheerful person who enjoys talking to others. He gets paranoid about me talking to other guys even though its harmless conversation. He says its my fault he is paranoid as I never help him to get better (which makes no sense to me as I dont know what to do!). Now he is saying he has had enough of my bullsh*t. I never lie to him so I dont know why he is like this. I am however really forgetful and am easily distracted which I think he really hates about me and takes it to mean that I dont care or I forget about him. I need help! He doesnt believe anything I say, I just want him to trust me. I just want him to know I care. How can I do this? I know he sounds like a bad person but he's not, he has anxiety problems and low self esteem. He also has mild OCD which I think makes him more paranoid. Please help :(

he needs prof help if its extreme but u cant change peoples nature either u adapt to it or leave him