How can i get my bf to trust me?

my bf is always arguing with me when i make little mistakes like miss a call off him because iv been downstairs something as little as that. we've been together a year n a half now and he always brings up the past and makes me up to be something im not. iv try'd so hard to be good to him i gave up everything for him and im always there no matter what. he has it easy to be ohnest, iv never told him to give up anything for me iv let him go out with his mates and have girl mates because i trust him, he is not all that bad he has been there for me from day1 and hes such a sweetheart, the problem is he carnt trust me because of the past even though he misunderstood my past iv explained everything and been totally ohnest with him but everytime i do he gets angry and im thinking thats the past iv changed for you, he picks on me for the littlest things i do and blames me all the time never himself i think he can be over the top at times about things and thats why we get in such big arguments and i dont want them. i avoid arguing with him beacause i dont want to lose him, im scared to confront him about the things he does that upset me because i dont wanna start on him otherwise it turns into an argument, he makes a big deal out of nothing and hes always pressurising me and giving me mixed signals one minute being comforting then the next thing he says something pressurising.he always acusses me of things i havnt done and i stress so much to make him believe that it puts are realtionship at risk.hes made mistakes to big ones but i dont turn against him i support him and help him look onto the furture and get over the stress he seems to get the wrong end of me at times and thinks il do this and that he told me he can never trust me even though iv done nothing wrong and its just hurtful, i want him to see the real me, iv tryed every way i just dont wanna break up over nothing tbh because i really have grown with him and hes my world,he says if i make a mistake again e.g dont pick my phone up like once hes threatning to leave me, sorry for blabbering on xx