Struggling with Intrusive Thoughts and Guilt

one day, around 3 months ago I had a thought while watching a show that it'd be nice to have someone like a character I liked in the show, and I didn't mean it in a relationship way but ever since then my relationship intrusive thiughts and guilt and self sabatoging has been so so bad since then. it started off small, and then its gotten progressively worse and I just feel like im in a hole. I know these thiughts aren't me and aren't how I actually feel most of the time but I csnt help but let them get to me, I just want to be like the perfect girlfriend. its not ever about my boyfriend and I never would want him to think so but the guilt for going through this in the first place is painful enough :( I just want to be happy with him again. I have days where I am, where those thoughts are useless chatter and go away but then I have days where I give into them, and the for weeks after I feel guilt for compulsing and checking myself.