How Long Can I Lie To Everyone Around Me?

I was quite the tomboy growing up. Most of my friends were boys because girls were too girly. I couldn't understand why they would want to wear dresses or have done up hair and why they would pretend to run at recess when the boys chased them.
I didn't ever think that I was gay because I didn't know that people could be gay. Does that make sense?
I never dreamed of settling down and having kids because I was raised to be an independent woman. I didn't need a man to support me! I could do it on my own.
I had plenty of boyfriends, plenty of one-nighters but it was all passing, there was no emotional attachment. I did it because I felt that it was the right thing to do. In high school, my parents asked me if I was gay. "Nope, not me." "Okay... because we'd still love you if you were." "That's great to know, but not me, I'm as straight as they come." and I believed it. After all, I had boyfriends, I couldn't be gay.
I didn't start to question my own sexuality until I was in college and my best friend, whom I adored, turned to me and kissed me straight on the lips. It was amazing! There were fireworks! My heart sung and I laughed! But I'm not gay!! It was just a kiss!!! What an idiot I was... and yet.. that was the turning point. I came home that summer from college and there was an older (well, older than me by about 10 years) woman that caught my eye. She was gorgeous. I would see her out at the bars and she would see me and smile and we would play that game of I see you and you see me... I asked some of my friends if she was gay.. hoping that she was.. and they laughed at me. "What makes you think that??? Why do you care??" "No reason..."
I went back to college and started sleeping with an old boyfriend. I was talking with him one night and said to him, "My parents think I'm gay. Isn't that funny?" He looked at me and said, "Well... not really. I always thought maybe you might be gay." I laughed at him. How funny. Me. Gay...
Eventually, I was pursued by a guy that liked me. We got together and after a few years I told him that if he wanted me to stay with him, we had to get married. So he proposed to me and I said yes.
I moved to a small town and found a new friend. She was full of life. Smart and gorgeous and sexy and funny and just totally amazing. We were the best of friends. We would walk down the street holding hands and I would lean against her when we watched tv and she would stroke my hair. But we were just friends. One night, she lost her key to the apartment building and climbed in through my bedroom window and landed on me. I woke up to her being on me and staring me in the face. I wanted to kiss her so badly but then we both laughed and she explained what happened and went to her apartment.
Eventually, I went back to college in a new town and while I was there I walked past the "Gay and Lesbian Student Center" about 100 times. Not because I was gay. I was just curious. Maybe I could join up and help them with a newsletter or something. It certainly wasn't because I was gay. I was engaged after all.
Meanwhile I split up with my fiance. Things had been going downhill for over a year and I just wasn't interested in spending the rest of my life with him.
I had a roommate and we worked at the same place on off shifts. One night around Christmas, we were in the livingroom and got pretty drunk. We were singing Christmas carols to each other and talking.. and started talking quieter and moving closer and eventually we kissed. We ended up making love for hours that night. After that things got cold between us. She had never identified as gay and was pretty religious, I think that it scared her and she pushed me away emotionally and psychologically. She moved out and I met a guy online and we fell in love and I married him.
Well, now, many years later, I have three kids and have been married for many years. When we were first married, I used to tell him, "you're the only man for me." It was true... I knew that if we ever split up, I could never be with another man. I ended up telling him that I had been with a woman before and he said that if I was ever with a woman, he would leave me.
In fact, we had split up for about a year and during that time I met and slept with a wonderful woman who lived quite a distance from me. She came to visit me a few times and we slept together a few times before we ended it and I went back to my husband.
In the past few years, I realize that I'm just not happy. Not because I'm married to him but because I'm married to HIM. Our sex life is diminishing more and more because more and more I accept who I really am.
I feel like I've gained weight so that he won't be interested in me anymore.
Now with the kids, I feel like I'm stuck. I don't want him to feel like he has to stay with me and I think he knows that there is something wrong. There is nobody in my life right now, other than him. I'm not cheating on him. I'm not flirting with anybody. I just know that what I have right now isn't right for me.
I need to stop lying to him and to myself. I am gay. Lesbian. I want to be able to just be me. Finally.