What do i do next.? do i cheat or get a divorce?

I've been married for just over over 2 years to my beautiful wife. When we were dating our relationship and sex life was outstanding. Right after I married her it seems like everything went down hill. For valentines day this year I made reservations at a nice restaurant and bought her a pair of one carrot diamond earrings. Things went great we had a great time however that night we still did not make love. The day of valentines I got her a card and some roses. She decided she wanted to to to a comady club with a few girlfriends so now im alone at home im kinda stuck... I love her with all my heart however when I try to talk to her about how I feel she insists nothing is wrong or she says all I do is think about sex.... some friendly advice would be appreciated