Trust.....

So not sure how to start this and what to add in and not but here it goes. So i have been dating my boyfriend for 2 years not but i dont trust him at all. when we first started dating after 2 months i found out he was talking to other girls and sending dirty text and things, but when i found out i told him i knew and he promised it would never happen again but it did even after being together for a year he did it again but this time it was with his ex, there was dirty text and picutres sent back and for and he was also going over to her house after work and telling me he was running late from work and stuff i found out and asked him if he was doing this stuff again and he said no but he did not know i knew about it all so i kept asking him but he always said no so about after 2 hours of him lieing me to i told him i knew about it all and he did not know what to say.... but again i forgave him and he promised nothing actually happend between them but i don't know if i can believe that. So after that things where ok but then she started texing him again and he said to me the last time he wants nothing to do with her but again he lied, and he told me that they want to be friends and friends only but i know and he knows that wont happen. so he was mad because in the end i told him it was me or her cause i cant go through all that **** again he said fine but he still believes that he should be able to friends with her and text and hangout..... but maybe i am wrong and they should be but i dont think its right after the things that happened. so now its been 4 months since all of this but i cant trust him with stuff i always feel like i should go through his phone to check, but he gets mad and says i just have to trust him, and when he goes to hangout with girls i just dont trust him at all. Also he has a friend now that stuff happened with through pics and text and stuff and they are still friends and they hangout at his apartment or just go out and hangout, and i feel like i cant trust him at all with her, i have not told him that because i think he will get mad about it and say he has ever right to hangout with her cause nothing has happened with her since that time........ Ugh so lost and dont know what too do. Dont know where to go from here

You have to read the writing on the wall. If he truly wanted to be with just you he would not continue to do the things he is doing. Give him the ultimatum of ending everything else and focusing on just you or you should move on. Period!