So I found out my boyfriend had texted two girls, one in August, one in November trying to clearly initiate sexual conversations. When I confronted him about it he lied to me. For weeks. Even though I saw the messages I doubted myself because he kept saying, "snapchat resends old messages", and that I  " don't trust him". In the messages when one of the girls said they don't want anything while he's in a relationship he said "well what if I wasn't, I'm torn". And "when I come visit we should be more than just friends". My question is, how do you move on from something like this and learn to trust again? I have major depression and anxiety and The thought of knowing the person I love and gave everything to could possible feel this way or do these things absolutely breaks my heart. I just want to move on but I'm so angry and hurt. I'm always having dreams about him being with another girl. He says he's sorry, only wants me forever, wants me to have his children and cried his eyes out in front of me and even gave me a promise ring for Christmas (before I found out). I love him, and always will. I just want our relationship to work out and do my part in moving on. I just really don't know how to. Any advice would be dearly appreciated. Thank you in advance.