Dude, she doesn't fuck you or suck you because she doesn't respect you and doesn't want to. Being a whiney pussy doesn't help. Seriously, end it. Or at least demote her from girlfriend status to random whatever status. The other option is just to take her sexually as you want her. Come home, throw her over your shoulder playfully, carry her to the bedroom, toss her on the bed, and put your dick in her mouth. Women love to be dominated. There is a reason why 50 Shades is the fastest selling book in human history. Taking her will turn her on.