Ok so it's weird I have a gf but when I see a pretty girl I start feeling really bad because my brain just starts showing how the future with them would be

I’ve been struggling with something that’s been really overwhelming, and I’m hoping to get some perspective from others here. I feel a lot of guilt about it, and I’m not sure if I’m alone in this experience. Lately, I’ve found myself daydreaming about romantic situations or getting caught up in ‘what if’ scenarios—where I wonder if I could develop feelings for someone else, or if someone develops feelings for me. The thing is, I’m in a relationship that I love, and I don’t want to act on these thoughts at all. What makes it even harder is that these thoughts often hyperfixate on one specific friend, and sometimes they feel entertaining or give me a dopamine rush. But then, of course, I feel even more guilty because it makes me feel like I’m betraying my boyfriend. These thoughts usually happen when I’m upset and looking for comfort, but then they morph into romantic scenarios, which makes me feel so disloyal. I’m constantly going back and forth between feeling curious or entertained by the thoughts and then feeling horrible for even allowing them to happen in the first place. I keep confessing these thoughts to my boyfriend, and he tries to be understanding. He’s just never been the type to daydream, so he doesn’t know if this is something other people experience or if it’s just me. I feel like such an awful girlfriend. Has anyone else dealt with something like this?

When I talk about how terrible I used to be to my girlfriend it makes me feel like I’m gonna do it again which I don’t wanna do and it scares me and then I get intrusive thoughts and feelings about it doing it but I don’t want to, weird I know.

So I identify as a lesbian and I am in a committed relationship with a wonderful girl. But i’m stressing that I have crushes on boys I go to school with. I get anxious around them, which I think I mistake for excitement. I obsess over it in my head which confuses me a lot. Idk I also never think about them sexually or romantically but I think about them often which is scaring me. Any advice?