What do i do with my relationship..

Long story short, i just received a message from a girl in my dm that my man was asking her for 'nudes' he told her she had a sexy body and wanted to see it.. this was about a couple months ago. I have been with my man for almost 5 years now. And this isn't the first incident.. i recently found out in june that 3 years ago he had sex with someone random because he was lonely... and that this year he kept messaging her for pics also in February.. my man has told me he has some type of sex problem because as a child he got raped by a man... im doing my best tbh but i feel like im at my breaking point.. I currently live with him and his parents because i have no were else to live and dont have the funds to be on my own.. i do love him and care about him i just need womanly advice /: