Just thought I'd share this latest societal "trend." Long story short, married and unmarried couples write up contracts to make each other happy. Surprise surprise, frequency of sex is included. Here's the article:

http://newyork.cbslocal.com/2013/04/29/relationship-contracts-growing-in-popularity-with-married-and-unmarried-couples/

I don't think it can get any more beta than this: instead of examining your relationship (and yourself) and fixing the underlying issues, you just make sex compulsory through force of law. Evidently she already doesn't want to have sex with you, I highly doubt that a piece of paper will turn things around. In fact, I'd imagine that pestering a woman for sex and then whining about contractual terms would only make things worse.