I went through the exact same scenario you just described when I was your age. I had always been attracted to guys, though, since I was a child, but at that age it wasn't sexual, just physical. I went through the motions of having a girlfriend all through high school and had even planned on marrying her once out of college. I had everything envisioned just as you do. I saw myself with a wife and children. I , however, unlike you, had already experimented with guys all throughout Jr. High and High School since I was 11. As a teenager I kept thinking those feelings for other guys would eventually go away and that this was just a phase. I had never had sex with a girl even though I dated the same girl all throughout high school. I did know that the sex that I had been having with guys, I liked! I like it a lot!
Once I got into college I finally came to grips with the fact that I was gay and that the pipe dream I had all along with a wife and children was just a blurry faded memory of something I knew would never come true. I came out to my family and friends. I took a gamble by doing that because being from the South I had heard all kinds of horror stories about friends who had come out and eventually kicked out of their family's homes. My family being well educated and progressive accepted my new lifestyle with open arms. I, after all, was still the same person they had raised from a baby.
I've been out now for 30 years and have never had any regrets over my decision to come out. If I had remained in the closet and wondered over the past 30 years what could have been, I'd be the most miserable person on the face of this Earth because I wasn't living my life for me, but for everyone else and trying to be the person I thought they wanted me to be.
I hope you make the right decisions concerning your needs and preferences and don't make yourself conform to a society that, when it comes down to it, could actually care less about who you are. Imagine the opportunities you'll miss out on if you don't allow yourself to be the person YOU should be. I have lived in San Francisco for fifteen years now and can honestly say that most of the guys who live here have the exact same story as yours and mine. Many of them still consider themselves bisexual, even though they haven't had sex with women in years. I think they just want to hang on to memories of their younger more viral lives. I can appreciate the beauty of women, but can honestly say that I have zero attraction for women nor even entertain the thought of someday having sex with a woman. It's just NOT there...
I wish you the best with your endeavors and decisions!