I have been experiencing a problem which has been giving me extreme anxiety lately and I wanted to run it by other individuals to get their thoughts.

I am currently in a relationship with a girl who I love. I would NEVER in a million years cheat on her.

Recently, I was at our house (we live together) by myself all day and I was feeling a bit 'on edge'. I decided to masturbate to get this edge off. While doing this, I decided to mentally take myself to a place I don't usually go. While watching a pornography video, I visualized myself performing these acts with another woman. Specifically, this other woman was someone I used to have a sexual relationship with, but do not (and will not) come in contact with at this point in my life.

Ever since this happened, I have felt a great amount of guilt and anxiety over this. I have started to convince myself that I cheated on my current girlfriend by watching this porn video and visualizing this fantasy with another woman, specifically another woman who I previously have sexual experience with. I want to emphasize that I have NO interest whatsoever in this past sexual partner. I would never act on this fantasy which I had, and just used it as an 'in the moment' experience to let my mind wander somewhere different.

At the time of doing this, I didn't think this was going to effect me the way that it has, since everything which I am feeling anxiety about is all in my mind. One side of me says that I am manufacturing this issue out of nothing, since everything I'm creating was strictly a mental fantasy. The other side of me says that my mental fantasy was extremely inappropriate, and I shouldn't have had this fantasy while in a relationship with my girlfriend. Obviously, anybody in a relationship would not want their significant other having fantasies about other people.

This is all I can think about right now, and it's causing me a great deal of guilt/anxiety. I wanted to get other people's thoughts regarding if my guilt is justified, if this is something which needs to be talked about, etc.

Thanks for reading.