Whats happening to us ?!?

I meet my boyfriend over a year ago, we hit it off very well, i adore him and he loves me! its perfect. But i dont trust him, he lyed to me and called me names and left me alone in his house while he was out with friends, and he laughs at things i feel strongly about. he used to take drugs and i couldnt stand it.so he got off them, but because of his slip ups i cant trust him, i feel like im losing battle, but i dont wanna let him go, i act like i dont care and i hate him, but deep down i just want to be with him. he has changed i know that, but the old him is still in there, he can be lazy and moody and nasty, but then hes amazing, loving and caring! he thinks im always up to no good, and im not, i try and convience him, he asks about my past which i hate dragging up, but he always asks questions and trys to make a lier outta me. i wish just for one day we were amazing together, that i could trust him and not be sniffing around him accusing him because of what he did, i know i shouldnt have ran back. But i have never loved someone so much, never will i ever love someone as much as him. So what should i do to stop the accusing, argueing and insercurities?