hello shaun and welcome to our community. it's good that you are working on these things with your therapist, who hopefully is a qualified mental health specialist knowledgeable in the field of male sexual abuse.
so many men come to this community tangled up in the barbed wire of confusion which our society imposes on them by enforcing people to think along the lines of black and white sexual binary, and causing them further grief, particularly when invested in a sexual self image that is contrary to one that aligns with a culturally assumed values system.
the truth is, it is very natural and healthy for men to fantasize about other men no matter what their reported orientation. seems to me, you have made a choice to be faithful to your partner, so that should eliminate any confusion, since all other options have been ruled out. maybe it would be helpful to just accept these desires and learn to live with them, rather than dancing with them by trying to deny they exist in the first place...... doing so merely reinforces their power over you.
abuse can leave us conflicted and twisted because we were brought up to believe that we 'should be' one way or the other. not so, and if you hang around this organization you will learn that soon enough.
this is a very complex issue, and one that will take time to sort out, but as you explore your sexuality in an affirming and positive healthy way, these types of questions lose their energetic power and dissolve in terms of their felt sense of importance.