Married and in love with someone else

A very long story is about to be drastically condensed here. My first kiss was when I was 8 years old. His name was Dan. We have been very close friends since we were children. I am now 36. He and I have both moved around the country at varying times but we always land back in our hometown either to live there again briefly or visiting friends/family. In those returns, we always have managed to seek each other out. When I go back home, he is always the first person I tried to find. I have been in love with him since I was a teen. I never EVER said anything to him about it because I didn't want to risk losing the most valuable friendship I have ever had. I waited until my mid 30's to finally get married. I have had an extremely rough past and didn't trust men very much as a result. I started seeing this guy in 2005. He was nice enough. Great guy. He proposed after 7 years. I said yes, thinking I do love him and this was likely as good as it was going to get! He is my best friend. He is a terrible husband. Not that he is abusive or mean or anything. He is just....well, it's like having a lazy room mate and poorly raised teenager all in one. I have expressed my unhappiness with how our relationship is time and again to no avail. I kind of resigned myself to the fate of being in a unfufilling marriage for the rest of forever. Well, the strangest thing happened a couple months ago. Dan, my first love mentioned above, decided to have a confessional one night while we were chatting. He confessed to me that he had been in love with me for the last 20 years. That he had to tell me. That he couldn't keep it to himself anymore. If that meant ruining our friendship then so be it. Needless to say, I was completely blindsided by this. He had assumed I picked up on his "signs" over the years but wasn't interested so I didn't reciprocate. Apparently, I am dense because I had not a single clue all this time that he had any feelings like that for me even though I wished with all my being that he wanted me. Dan is miserably married. He married her because she was pregnant years ago and feels obligated to stay because of the kids. Neither of us would have married these people if we had an inkling of each others feelings. I found myself back home for a week recently and got to spend time with him. We stole a night together and it was absolutely incredible. While we were certainly having an affair, it didn't FEEL that way. The amount of pent up passion and love we have for each other canceled everything else out. I don't feel guilty about it at all. I think it's because I truly believe I was supposed to be with him all along and he feels the same. Leaving him there to come back has been heartwrenching. I feel like a piece of me is gone. We are both having a very difficult time with this parting. Our story is the stuff of chick flicks. We are both married; he miserable in his and I am not miserable, but certainly not happy. It could be worse for me I guess. Here's my quandry: Even prior to Dan's confession to me, I already instituted the "5 year plan". Simply put, either my husband gets his sh*t together by the time my kids move out (not his kids) or I am leaving. I have expressed over and over again that things in this relationship are making me unhappy and asked him to work with me to improve them (we actually split up for awhile due to this exact thing. He cried. I came back). This has repeatedly fallen on deaf ears. But now, the 5 years seems like an eternity. I know my leaving will kill him. He's not a bad guy. He is a GREAT friend to me and everyone. He is just NOT a great husband. I love him. But its more like a platonic love now than a romantic love. I absolutely hate living with him so that doesn't help. We have been together since 2005. Lived together since 2006 and got married in 2012. I married him because I needed security. Everything is in his name and if he kicked, my kids and I would be out on the street with no more house and no more car. I have started from 0 too many times to want to do it again. I had to protect my kids. Their father is dead and another uprooting is more than they needed. Had I known about Dan all this time, I would not be married, I would not even have moved in with my husband. That one little piece of info would have changed the course of so many events. I am just at a complete loss as to what to do here. I'm not a horrible person. I think I am going to stick to my original 5 year plan but it was going to be hard to last that long even before I knew about Dan. Now its just excrutiating to think about. I love Dan with every fiber of my being. I always have. I know him better than I know anyone on earth. He is a beautiful soul. But, ultimately I have these obligatoins to my husband and my kids. My daughter is going to college next year and I am not selfish enough to ruin that for her because if I leave my husband, I will not be able to afford to put her through school. My son will be 18 in 4 years. I can't uproot him again. It's all so d*mn complicated now. If I only knew what I know now......I have never been happy. Truly happy. Not even once. Now, I know I can be down the road but I can't have it right now without hurting a bunch of people. Thoughts?

One day at a time. Stay positive and think only about good times. LOVE is the key to everything. You are caught up in a love triangle, thousands of people are so therefore; you are not alone. You're a mother first and must have shelter(a safe haven), food, clothings and necessites for your children. Your husband is a good man for providing for you and your children. Dan is a good man for taking on the responsiblity of doing the right thing for the lady that he married. In the end everything will balance itself out and everyone will be happy. Time holds the answers to all of your questions.