Funky Girl,
I know exactly what you mean. I'm currently in an 18 month relationship which is making me unhappy. Why? Because I don't think she's the one! Why? Because Lizzie is! Lizzie was my best friend / on off girlfriend for 3 years while at university - I knew she was the one for me, we were soul mate! But....she didn't seem to think so!
My current GF is fantastic, but I'm constantly fighting the relationship because I know I am capable of stronger feelings. I love her but not as much as I loved Lizzie! Which is causing major probs! My life is going stale, I'm not moving on, I don't know my future. It's very tough and not much fun.
I think if you still have feelings for someone else it always is hard. If you're like me you probably wish you were single simply because being in a relationship (in your case married) means that you can't have him....or maybe you think that it means even if he did want you you'd never know because he'd never tell you - after all you are married!
I don't know about getting in touch. Is he in a relationship? Would he want you? He may not! In which case you have to ask....am I only unhappy with my marriage because of my love for him? Or, am I unhappy because the relationship I'm in isn't right? It sounds like you are having doubts!
Even if he didn't want you would you still like to be 'available' again?
If so...maybe it's not your this old BF you want to be with, just someone more like him.
Hope this has helped you a bit. Sorry if I have gone on..just sounds like our situation is so simlar I thought it might help!
x Matt