Wow Emma gotta say, your story is eerily similar to crap I’m dealing with.

I too have been in a relationship for ten years and am getting married next year. We also drifted apart some time ago, but where our stories differ is the affair [though if I’m honest mines an emotional affair] So I know how you feel having thoughts of this other guy and wanting it to stop.

I’m going to mention Polyamory, but I’m not advocating it. I know many are against it, but if you feel your relationship is strong enough, discuss it. If you’re a monogamous type ignore this point. [I’ve always been fine with Polyamory, I just know I couldn’t handle it emotionally at this time]

SO, advice. Firstly, I would continue with your therapy or at least some form of self-help work [journaling for instance] to work through these thoughts. Suppressing or ignoring will cause it to fester. Distance is another wise move, blocking this person is a wise move to ensure he doesn’t appear again. Contemplate what draws you to your fiance as well as this other guy. [personal: my fiance and the other guy are very similar, but the other guy is new, exciting, fun, while my fiance is comfortable, safe, predictable. So we’re ensuring we have date night once a week, talk more, surprise each other with little things] You might also consider the old fashion pro’s con’s list, but there’s one my therapist gave me that’s four squares, pro’s and cons of things staying the same, and the pro’s and con’s of things changing. That one helped me with a few decisions.

I would also throw out the old “cold feet” argument. You’ve chosen this one person forever, this shuts the door on other people forever. That’s scary. You’ve given up the freedom, a small part of your personal power. Henceforth, you’re a unit, and can’t simply go to the movies after work with friends, you need to text your husband and inform him of this [and vice versa if he wants to randomly hang with his friends, he needs to check with you] for some people, this is a level of control, and it can be scary. You are technically losing things [hypothetically] but think of all the things you gain. I know how easy it is to look at the closed door but think of all the things you gain with your partner. Think of all the reasons you love him. Think of the future you see with him. You may wish to compare it to the future you see with this other person, but depending on your mental state [I can get stuck on an idea/thought and spiral] you may wish to avoid fantasizing.

Good luck to you.