Is my bf a liar, cheater & a pedo?

I need some serious advice because I’ve been keeping this to myself for the last 3 months, and its been eating me alive emotionally. My bf and I have been together for 3 years now, I fell absolutely in love with him because he was so kind and sweet. Our relationships had ups and downs surrounding substance abuse and a toxic friend in the beginning. The substance abuse has gotten a lot better, and the toxic friend is gone, at my boyfriends free-will; I didn’t want to force him to stop being friends with him. Anyhow, recently my bf told me he has been lying to me about his past. To add; when we first got together he told me I was his first everything, including first date. I was so surprised, but knew I wanted to treat him special and make him absolutely happy (he comes from a broken family, as do I). He later dropped a huge bomb and told me before me he was with a girl romantically and sexually but they never had sex before he met me, he said he used her to “feel something”, he even told this girl he loved her and what not. On top of that, he told me was addicted to porn and soliciting photos and sexting girls (in the past). He also admitted to a scenario in which he sexted a 13 year old girl. She lied about her age, she told him she was 16, and he at the time was 19. She LATER told him she lied about her age and he still asked for the photos, she never sent any but he sent some to her of his private parts. He also masturbated while sexting her. Ladies, please ....what do I do after all these lies?