Bf Messaged another girl

My bf (25M) and I(23F) have been together since May 1st of 2021. We moved in together May of 2022. Beginning our relationship was rough, we were long distance and a girl messaged me stating she saw him on Tinder and he admitted to using tinder to message other girls. We worked through that and were able to have an amazing relationship for over a year now. He has never had positive male role models in his life and his father currently has 5 girlfriends, so I knew that our relationship may face some strain in this area. Today a girl messaged me stating that they had previous relations (before we were together) and she had cut things off with him and they weren’t in contact. She had messaged him a couple months ago with a harmless question (about car insurance) and he gave a simple response and that was it. But then she told me that he messaged her last month (June 8) and asked for her to snapchat him. She didn’t respond or act on it so nothing ever came of it other than him sending a message. She came to me telling me all of this because she had a bad experience with him and when she saw he was in a relationship, she reached out to me to let me know (and i thanked her profusely for doing so). I immediately confronted him and his excuse was that things were so hard for us when we first moved in (I suffer from chronic depression and had an episode where I was in bed for a week) and that he was panicking about not feeling fulfilled from me and that’s what drove him to seek outside of the relationship. He claims nothing ever happened with her, which she confirmed because she didn’t acknowledge him. I have concerns that she wasn’t the only girl he may have tried to talk to or that I am looking stupid thinking this man truly wants to be with me and marry me. Living together has been hard on both of us, due to money being tight, living 3 hours away from anyone we know, and my mental health has been really poor. His love language is physical touch, which can be hard for me to give when my depression is really bad, which he said has a big impact on him. I completely understand why that would make him feel not content in our relationship, but it still is no excuse to be messaging other girls. He claims he wants to be with me forever, and has asked my entire family for permission to marry me, we have even tried on rings. He swears on his life he has never met up with another girl and says he has never “cheated.” He has been working on his emotional intelligence like identifying how he’s feeling and why, as well as coming to me with these feelings and being transparent about them. My question is, do I let it go and just hope to work on how to love each other better? Or am I making a fool out of myself thinking he will choose me and only me? No man has made me feel as good as he does, but I don’t want to be so blinded by love that I can’t see if its not being reciprocated. Help 🙁 -from a very insecure young girl who maybe loves this man a little too much

TL;DR- Got a message from another girl that my bf of over a year is messaging her to snapchat him. He says he looked outside of our relationship when things were rough between us but claims nothing ever happened.