heavy weight on my shoulders

I don’t know why I’m so nervous/scared typing this out, but this has been on my mind for too long and I feel like it’s eating me alive sometimes.I was friend’s with this girl I was pretty close with. We definitely spent a good amount of time with each other. I met this guy that goes to my school, and he approached me like he seemed interested in me. I’ve never really been in a relationship nor a “thing” with a guy, so I went for it and I was excited. The thing is, my friend and the guy were fwb for a little bit, so I was a little uncertain about it but she told me to go for it so I did. Me and the guy met in May and talked throughout the entire summer (even though he was in another state). I was really happy with him and even my friends told me I was “glowing with happiness”. Fall semester came around, we weren’t dating because I found out he just wanted to hook up the entire time. I was obviously very confused and hurt, but I still ended up going back to him even though there were so many red flags. He is a very manipulative person and knows how to sweet talk into things. I tend to have traits where I am too nice sometimes, so he took advantage of that and started using me for his own good. Since I still had feelings, I didn’t see all of that. I didn’t think anything of it and thought it was okay. My friend told me that he ended up raping her by manipulating back when they were in that type of relationship. I felt absolutely terrible.However, I let my morals down and still went to him. He didnt know that I knew what happened between them, so he thought everything was fine. Every time I would go back to him, I felt so guilty but it’s like I didn’t want to let go. Like I said before, he is very manipulative and knew how to get me to stay in the relationship we had (fwb). I also felt like every time I saw my friend, I couldn’t even say hi to her because I felt so guilty.I realized that I took too long to make the right decision, but I ended up cutting ties with the guy and telling my friend the mistakes I have made and apologizing to her. I knew what I did and I know it’s so wrong of me to do. She ended up forgiving me and we are friends now (not as close as we were before), but I’m grateful for her to even be friends. Even though everything is okay, I still feel so much guilt. It’s been months and I haven’t forgave myself yet. I know everyone makes mistakes, but I feel like this is something that is more than a simple mistake — it’s just terribly wrong. I have definitely grown from this and I’m continuing to do better, reading more self development books, reevaluating everything I do, etc., but this is still in the back of my mind.Thank you for your time, and I hope you have a good day/night.