Sexual and psyical help

Help I hope you can help me with this as I am getting nowhere here at home tring to sort it out. My Question is a long one and in a few parts so here goes. I am in a relationship headed towards marrage. We were so stronge and close full of love and support. Lots of hugging, kissing etc and very sexually active. Now for the last 3 months my partiner has totally shut off to me in all areas psyical. I ask for a hug she says no I ask to hold her in bed or anywhere for that matter I get a no not a maybe or later a no. She wont even ponder the sexual side it is just all gone.

She loves me I am sure but just wont touch me or let me touch her without acting as if it is a chore or makes her uncomfortable. I have come to the conclusion I want to find a way to end my sex drive once and for all as I have no use for it and all it brings me as of late is grief and upset. How can I get rid of all sexual desires so I dont crave her no more like she dosent crave me. I am totally willing to be married and live with her happy as I always have been without the sex and I guess with no affection. If that is what she wants I support her and will do all I can. I mostly want to know what I can do to erase all traces of sexual desire as if I dont I will be bothered from it and I dont want to bother her with my pittiful desires. Thank you for your time.
Joe