OK firstly I must qualify by saying this is my first ever post on here. I joined as I am in need of some help myself. I stumbled upon your post however and couldn't go past it as I think I can offer some advice based on experience.
I am a gay man and have always known it - since I was a teen. I married my best friend (female in the 1990's when I was in my 20's as that is "what was expected" by my family and society. At the time I didn't regret the decision at all as I wanted a family and the only way I could see to do that was to be with a woman. And marrying my best friend - well what could go wrong there?
So what has gone wrong is that my sexuality has slowly been eating away at me for the past 20 something years and I haven't acknowledged it creeping up on me. Then to my own horror, I did the unthinkable a couple of years ago - I had an affair - with a man. There was a lot going on in my life at the time, but I was well aware of what I was doing and put the blame squarely on myself. It wasn't the fault of my lover or my work or my health issues - it was my fault for not acknowledging from the start my true desires.
Now some 27 years after meeting my then future wife for the first time, and looking down the barrel of hitting the ripe old age of 50 soon, I have realised that I made the biggest mistake of my life. I followed what everyone else wanted - not what I wanted. I was too scared to do what I wanted in fear of reprisal. The result is that now I am "stuck" in a relationship that I can't see holding together for much longer. To follow my true desires, I now need to make the next step beyond the unthinkable affair and essentially destroy my family - the family that I have loved and nurtured for so many years.
It is almost at the time where I will have to pull the pin and cop whatever fallout it causes, but I now so wish that I had followed my true self way back then, than have to do it now when it is so much more damaging to everyone.
Yes, I am in a pretty crappy place right now and I am struggling to see the best way through that causes the least collateral damage, but if my advice is worth a dime, I say to you - follow your heart, no one else's. In the long run it will be for the best. If you do what you really want, then those that truly love you will follow and stand by you. Those that leave you are not friends.
If you don't follow your heart, then it will catch up with you one day and life's struggles will be very different then.