All the best to you and remember to take care of yourself too, for you. Exercise, keep fit, trim and healthy, if you look good you will feel good about yourself, eat well, sleep well and don't fret. Also remember that it might help to have a big dose of empathy for your H. Shift the focus away from yourself ie. "I'm feeling so unhappy in this M because I'm not getting this and that from it" etc and try to step into your Hs shoes instead. I know you've said its hard but give it a shot, its worth it.
I hope you won't feel too discouraged by the many Hders here who have been trying for years and yet see no results. Everyone's sitch is different. There are just too many dynamics involved in a relationship between H and W. Only you know your sitch well enough and whether its worth whatever path you wish to take it.
To those who have been trying for years, are perfectly happy with themselves etc and yet whose spouses continue to be in denial or to ignore the problem, I do wonder whats keeping you from leaving. Why stay in a M when you are feeling so unhappy? Why stay in a M thats abusive? (if you feel that witholding sex from your spouse is a form of abuse then why stay and be abused?
If you are staying because of children, thats a good reason but then you have made a choice so why not try to be as happy as you can be under the circumstances? If you are staying because you fear your leaving might be devastating to your spouse, well, you are not responsible for another's happiness just as they are not responsible for yours.
If you are feeling so unhappy and feel that you cannot go on living in a M where you have to surpress your sexuality and its beggining to make you sick even, then why stay?
I hope I haven't offended anyone but I just don't get it. If you feel that your M is worth it then work at it 101% and if you feel that you have done all you can and yet........ why stay and complain about how miserable you feel. You don't have to stay miserable, you have a choice.