So, me and my girlfriend have known each other since August of 2018 and we first dated in September of 2018 and we dated until November of 2019, because we more or less just needed more time to develop. We started dating again in September of 2020, and during our time apart we both wanted to get back together, but we both did each other wrong and slept with other people right before we planned on getting back together. Things are going good now, but always in the back of my head I feel that she is cheating on me behind my back and faking love with me, though I don't really have any evidence to prove this. However, one time I was at her house and she got a text on her phone that said "wtm can I pick you up tonight?" from an unsaved number, and I asked who that was and she said it was the guy she slept with before we got back together. She swore up and down that she has not been talking to him, and that she had not done so since we got back together. I just don't understand why I feel the way that I do. I have a lot of flashbacks from the girl that I was with when me and her were apart and she was a hoe and she lied and cheated on me, now I feel as if my girlfriend now would do the same. She's always there for me when I need her and anytime I tell her that I'm worried about her doing something like that she always tells me that she would never do that to me, and she just says a lot of other things in order to reassure me. I just want help and I don't want to worry about this kind of thing every single day because it just makes me contemplate everything... Yesterday she had to go to our school to take some exam and the guy that she was fucking when we weren't together was there, and it just made me so anxious that something was going to happen, but my friend told me that they never spoke and they sat nowhere near each other and my girlfriend said she thinks she saw him try to nod at her but she just ignored him. I trust her with my whole heart, but I just don't know how to explain what I'm feeling...I trust her but it's just this subconscious thought that I have about the girl that I was with before. What can I do in order to help completely remove all of my worries about this situation. I'm sorry if this was long I just felt like a keyboard warrior Andy.