Thank you for writing to Just Answer.
If you want to face your problem squarely, you have to get right within yourself first.
You have two conflicting desires: On the one hand, you have same sex desires.
On the other hand, you are desiring your daughter. I know she is a step-daughter, but you have been in her life as a father for most of her
life, and you must behave as such unless you don't care about hurting her (and her mother).
When one truly loves another person, one wants only the best for them.
Imagine that your daughter came to you and said that her Uncle, who may be homosexual although not decided yet, and who is married, wanted to have sex with her. You would probably be very angry and concerned, and tell her to stay far away from him. It would not be the best for HER.
To approach a young woman sexually after you have married her mother and acted as her father for so many years would be deeply traumatic to her.
It is one thing to have fantasies, but you will destroy two lives (mother and daughter's) by acting on your desires.
It would be safest and fairest for all involved for you to remove yourself from this situation so that you don't take a chance of acting incestually (or step-incestually) with this young woman.
Facing your problem squarely means making the right choice for those you have loved.
It does not mean declaring your attraction to your step-daughter.
It means that you need to do some intensive therapy--telling the whole truth this time--and figure out your sexual orientation. It may be that this attraction to your daughter is a "flight" away from the homosexual thoughts you have had all your life. By forming an attraction, you can submerge those thoughts for a while.
But if your true orientation is homosexual, it will always interfere with your ability to form intimate relationships with women...you will always be left unfulfilled. Find a counselor who specializes in sexual orientation issues
and figure this out. Here's a link
to find a gay-friendly therapist if you don't feel comfortable confiding in this issue with your current therapist. Here's another link for finding therapists
experienced with this issue.
This is the way to face your problem squarely. Get right within yourself, be true to who you are, and do your best not to cause any damage to others as you make the necessary changes in your life to make it more congruent with who you are.
I wish you the best,