Saffie has some wise advice, Mark's advice is great too, but like Puppy has pointed out, I don't think WDID is ready.
My suggestion WDID.... don't leave your marriage for OM. Dump him either way. If you are going to leave, leave for yourself and some future healthy realtionship. Logically, the chances of any guy who is pursuing a married woman being worthwhile is very low. A married woman going through divorce is going to have huge baggage. She's going to be an unhappy woman, struggling with self-esteem, low ego, guilt, depression, etc... What kind of guy seeks out this? What kind of guy seeks out a vulnerable woman? Usually someone who can't get a healthy one, and that should be a red flag that he has a problem.
Do yourself a favor and truly improve your life. Don't leave an unhappy, depressing, situation for something that has the potential of turning into a nightmare. You need to dump OM and focus on yourself. Once you are healthy (like in a year or two) then figure out if OM, or H, or someone else is what you want. The longer you spend wasting time with OM, the longer it's going to take you to clear up your head, get away from the confusing emotional turmoil, and really figure out what you truly need to make yourself healthy and ultimately happy.
There is no arriving, ever. It is all a continual becoming.
