Should I stay or go??????????

I have been with my Boyfriend for 1 year. We have broken up several times but we wiind up together again. First time I left I caught him emailing another woman. He never has met her But he talked about his life and not mentioning he was with me. He told me he did not know what he wanted. He panic and wanted me back an proposed to me. He has been ill lately . Not sure what he has. He loses his temper . I never asked for much he has 2 kids one lives with him. He has financal problems he has a job but he is not happy he is use to make more money than that. He use to be a swinger in his marriage with his wife. He has been on craigs list posting ads for a BJ BUDDY. I do not trust him but I want totrust but He looks at porn. Says he is making love to me with 99% of his heart so his is thinking of someone else. He placed a ad on craigslist Men looking for men But deleted it. I can check his email. He can check my too. HE HAS DONE it be fore. Think i should leave. I am so stressed but he throws the BETTER OR WORSE card andhooks me with some thing else I found out he answered ads on craigslist for men 4 menIn the casual encounters. He said abut porn he is curious but the answering ads on craigslist?