Maybe I should just let him go now :(

for just over a year my bf and I have had alot of trust issues. I didnt have an ounce of trust for him since he cheated on me, all the proof was there in plain sight...but im not an angel either, i've done horrible things also, but I havent repeadidly cheated on him the way he did to me. I have found his many e-mail addresses with links to other chat/dating sights, e-mails to various women, dik pics and nudies from other women, txts, phone calls, the works....it hurt alot!! finding all of that peice by peice...right when i though i was healing i would find something else, he would forget to log out of his email addresses or wouldnt clear his history from the computer. Was he wanting to get caught? I think so but when i confronted him why did he allow me to stay and keep doing it? after many promises that he made....well i decided that im going to google ways to not get caught cheating just to see what kind of things he was reading about it, tips n stuff because he was really sloppy with it. Then he found my cell phone in the bathroom (i forgot it) and he went through it and for the first time he found something that broke his heart, the first time i decide to look on google was of course the first time he actually found something....Now i dont know wut to do.Is it not fair to me or not fair to him? I have to admit i feel heartbroken because i hurt him like that and i dont have the heart to cheat. i love him unconditionally. How did he have the heart to cheat repeadidly? well now he thinks im going to cheat and and theres probably nothing i can do or say that will convince him otherwise because im not convinced either that he will stay faithful....Should i let him go now?? Im so hurt by all this ongoing lies and cheating nonsense and i regret googleling how to cheat and not get caught......I dont have the heart to....
sorry for the bad spelling