A month ago, I caught my boyfriend sending texts to an ex, it was the first time he did it in our relationship; he has a history of cheating on his ex and unnecessarily lied to me a few times about talking a& seeing a friend/ex(affair) (he cheated on his ex with her but they were friends before). I didn't think he would cheat on me due to our history and how we ended up together again after nearly 12yrs. But when I saw what he said, I was devastated (still am). We broke up for a few days until I was ready to talk, I've known him since I was 14 (31 now, he was my 1st love and this is our second chance) and I love him completely and want to believe we can work it out, but it hasn't been easy. Mainly for me because of what he did. I'm convinced I wasn't enough and that he'll do it again. He said it was a mistake and he knows that what he did was wrong. But he locked his phone up so I can't check it no more. He also hasn't been as affectionate and this has been the longest we've gone without having sex. I feel things have changed between us and I don't know how to talk to him without him getting upset that I'm bringing it up again. There's days where he's more affectionate than others and days were I feel more like a friend. I'm lost in this whole thing. Does he love me or not? Idk anymore. He does work very hard and gets up super early, so I understand him being tired and exhausted.... but I can't help but feel that there's a distance growing between us and that maybe he's talking to her again or someone else. It feels like he's giving attention to someone else because I don't feel it anymore. Could I just be overthinking or paranoid? All this has made me insecure and doubting my relationship.

Edit: To explain our history a bit and to clarify why I believed he wouldn't cheat, we talked about his past and he openly admitted that he wasn't proud of the man and the choices he made, he said he isn't that person and I believe people can and will change is they want to. I know I did. We also have a unique history. We kept in touch through out the years, nothing bad but simple "hello, how are you." I reached out after my father passed away because he knew my father from us dating for 4 yrs in high school. He reached out to see how I was a few years later and then again just before we started dating. Through out the years he always wanted to be friends but I had a boyfriend who didnt like us speaking, so we would stop talking. A few years ago when things were starting to fall apart in my previous relationship, my bf now and I started talking again. It was honestly the best conversation I had, like two friends catching up over coffee. We talked about art, music, movies, plays... things my ex and I never shared an interest in together. Slowly but surely, I began to feel those old emotions rekindling and ended it before things went too far. He also exclaimed he shared the same feelings for me. Even as teenagers he called us soulmates and wanted to marry and have kids with me. I broke his heart after high school when I broke up with him. He said that he was never truly happy with anyone after that because all he ever wanted was me back. We've been together for a little over a yr, we live together, and his family and I get along well. He also has 2 kids from his ex that I also get along with and absolutely love and adore.