<human>: Can you give me the gist of the text in a nutshell?

I've been in a relationship for six months. I'm 22 female, and my boyfriend is 23. 

Before we got into a relationship,  I was pining over a guy (NOT my present boyfriend) like a schoolgirl. If I had a trapper keeper, I'm sure his name would be on them. And because I felt this way, whenever he wanted to hang out and just relax, I would stiff him. I didn't want it to burst out in front of him because I am NOT used to feeling that way at all. I had no idea what would come out of me haha. I also had drunken sex with his brother around that time and I felt like a giant flooze and hypocrite. 

So fast forward a few months, and I'm actually in a relationship. 
I seriously regret the way I acted and handled things. I had this great chance to get to know someone who was really chill, and because I was hung up on wanting a relationship, I started dating someone and let my emotions get in the way. And I feel bad because I do care about my current boyfriend, but it started off on completely wrong terms and it honestly just feels like a lie. But it's hard because I really do care about him. I've tried breaking up with him, but I always think maybe I'm just doing the relationship thing wrong. So we get back together. This is my first "serious" relationship, so it's just a lot of learning here.
<bot>: But I guess my real question is, do you think my fantasizing over that kid is what's putting a rift between me and my boyfriend? Am I naïve for thinking there's something between me and that other guy?