Sorry to hear this brother.
I see it this way. You need to do at least one of these things:
1) Tell her that just because she's not interested doesn't mean you aren't and you would like to use her body for your pleasure on a regular basis (you tell her how often that is).
2) If she doesn't want to do the above, then you ask/tell her that you will seek sex outside the marriage. You still love her and would rather have sex with her, but since she's not willing, you must find it elsewhere. It is good/necessary for a man's mental health at a minimum and some evidence says physical health too.
3) If she will not go along with either of the above two choices (#1 is very reasonable), then you tell her you ARE going to seek sex outside the marriage whether she wants you to or not and that if she can't be married to you because of that, then that's how that will be.
4) Of course you MIGHT want a partner who enjoys sex also, and if that's the case, she's not the one for you and you'll have to do some soul searching to determine if you can stay with her.