Please talk to her immediately about your concerns..I was in the same situation and felt my fiance didnt wnat sex as much as me but it was all a misunderstanding and now we do things together and although its still hard to talk about I knwo now its better to get things out in the open..We are getting married this month and I told him Saturday night a few of my concerns andwe worked it out..Just my 2 cents here but I hope you can talk to her