Did I mess up? What do I do now?

I (F 22) looked through my fiancés (M 22) phone. I’ve had an off feeling for a little bit (I’m not proud of it, I shouldn’t have and I regret doing it). I didn’t find him cheating on me, I think. I found texts between him and other girls (randoms) from when we were talking (September 2024). He was texting them the same things he was texting me- the updates, the compliments, the flirting, the questions, etc. He was also texting a girl- who we both know; he works with her, she’s just at a different location now. I don’t personally like her and my feeling about her being a weirdo ended up being right and I’m glad I keep my distance. Anyways, he was texting her like the other girls but she’s the only one he continued texting that way when we started dating. He has said that she’s just like a sister to him- personally after reading those texts I would never text my brother that way but alright. He stopped the texting everyday with her this past May- we’ve been dating since October 2024, got engaged October 2025. I honestly don’t know what to do. My heart hurts, but it’s only my fault because I snooped. I feel like I’m the only one who stuck around and that’s why he’s with me. I want to bring it up but I feel awful that I snooped. There’s 100 feelings and thoughts going at the same time and I’m stuck. What do I do and how should I be feeling?