First off you have to look at sex in a positive manner, it can change the way you feel about certain things.

Sometimes there is an underlying problem whether it be physical or mentally, you should talk to a doctor an rule somethings out but try some natural things.

Take a vacation (even if its at home) sometimes stress can completely take away the mood, so relaxing before hand can really help, taking a bath, having a glass of wine/beer or even him giving you a massage.

I dont know what it is but its like the later part of a relationship alot of men forget about the foreplay part and therefore you look at sex as boring or you forget to spice things up abit, like changing location or doing something a little crazy. Sometimes you wish men would do something differently but then never voice your thoughts on it and only get frustrated, that is why communication is important. This is like reading my situation backwards and I can understand your fiance but I can also understand your points as well, it is frustrating, the wanting and the not wanting but there is always a solution.

I also used to have a high sex drive and have lost it. I don't think there is anything medically wrong with me. It has to do with having three kids in four years and being tired all the time. I tell my husband he needs to do more to help me so I can relax and want to be with him. He doesn't listen. I don't know what to do because I just don't ever feel the need to have sex. I believe a lot of this does have to do with our energy level, mind set, and emotions. If anyone has a way to get a man to listen and understand when you tell him sex begins long before the bedroom, let me know.

I also agree communication is very important, you might also try some new position, toys or new places to feel more excitement. Maybe you just got cought up in routine life too much. A friend of mine had the same problem and then started tryng all sorts of new things and it really helped her and her husbant.

Are you on hormonal birth control? There was a scientific study done in the last year or so, and it was well conducted. In the study they found that The Pill make one in ten women who take it become unable to desire or enjoy sex, and unable to orgasm. In some women it just lowers the libido, and it makes other women frigid. It can take years and years for the effect of The Pill to go away. In the study, for seven years they followed the women whose sex drive was diminished by the pill, and seven years after going off the pill they were not yet back to normal in their naturally produced hormones (checked by blood test) and in their sex drives. The study ended after seven years, so they never found out if these women ever went back to being like they were before they ever took the pill. You can do a web search to find this study. In the study they discovered that taking any kind of hormone by mouth will cause changes in the liver, changes which make the liver become a hormone incapacitor, so to speak. The liver produces a lot of little things that are proteins that bind to hormones in the blood and change them so that they won't work, and taking The Pill will make the liver produce more and more of these globulins, or proteins.