HELP BOYFRIEND LIED

So my boyfriend of 2 and a half years lied to me for our whole relationship. He told me that he had sex with 4 girls before me. Then I find out from his sister that there was one more and it's his friend that he still helps her with stuff and I knew her. I joe for a fact that he didn't cheat on me but he lied to me and left her out when he told me who he had sex with. Then yesterday I find out that he had sex with her multiple times about 5 years ago and I was hurt that he could lie to me for so long. I told him I sensed something happened between the two of them and i need advice on what to do. I love him it's just my trust in him is all gone. He said he was gonna fix it that he was gonna tell her they can't be friends because of their past and I said if he tells her that just make sure to tell her it's temprifafg until I process everything. What do I do???