That sounds like a long, dark, difficult time in your life. I can relate because my husband had an affair and is also working all the time. It's good that your kids are older so whatever happens now will have slightly less impact on them. Technically you've already been living on your own without the love and support from a husband you've wished for since your husband hasn't reciprocated in so long. Your life won't be so different if you get divorced except you'd be free to meet a new man. I'm still figuring things out myself so I'm not sure there's much I can suggest except that it's just so hard to engage someone who doesn't care about you. Your choices are somewhat limited if he's not communicating. Maybe you really need to take a radical approach and prepare yourself for separation and divorce and follow-through and then you'll see if he has a change of heart. Otherwise this has gone on for so long that nothing may change any time soon. One would wonder why your husband isn't the one to request a divorce, or tell you himself he wants to leave, if he has no interest in working on the marriage? That doesn't seem fair. I hope you can share what's holding you back from freeing yourself from this marriage. I myself would like to know since I'm in a similar position!
