If the lack of sex is causing you to write posts like this, then you should talk to her. You could always try suggesting it earlier in the night. Oh and having an orgasm relieves headaches.
http://www.livescience.com/27642-sex-relieves-migraine-pain.html. Should be the same concept.
Of course it's lack of sex, at least as a nr. 1 thing. Then we could talk about other things like her sucking it sometime, dressing up certain way, or accompanying me to some places etc. From there I guess new needs and desires would go on and on...it's like that hierarchy of needs thing lol. That's why I said that desires progress faster than any relationship can develop, and unless you happen to find an amazingly flexible and open minded person you'll always resent monogamy in one way or another. Couple that with "lack of options" (real or perceived) i.e. having to be around cuz not having anywhere else to go, and you feel trapped.
In order to cheat, you need solid financial resources. If you've moved in together with your gf that means buying or renting another flat, having enough free time, or going to hookers which costs $$$. Those hot professional ladies ain't fulfilling your desires for free, are they?
And while some girls are not so openly materialistic when it comes to their bfs or husbands, I argue that still everything would go much smoother if I could now pull out a fancy trip to some island or at least some 5* SPA to "cure" those headaches of hers and all that "tiredness", including the best doctors to be here everyday (giving all the attention she wants 24h/24h and )trying to figure out what's wrong with her sex drive and some other organs.
Or I could be like Richard with a naked model on his back and just say fuck it all and have fun in the moment when I want it....
But not, I am constrained by the environment and resources. That's why I can't give anything 'back' to anyone, since I have no capacity to do that, one who always feel like missing everything ain't giving anything to anyone (and that might include love, attention, etc. or simply advice) Here we come basically to the chicken egg dilemma.
And btw, she promised me sex Saturday night 4 days ago lol

What a long term planning! It's not like I am asking for it everyday. What you think would I put up with this shit if I had like millions in bank? I could just take my wallet and walk out right now and live the life however I want it. Have time to think, re-think, try out, explore...But not. The fucking clock is fast, free time is scarce, thinking time next to zero and that's how our lives will pass. The bright moment of the day is when you put your headphones and let yourself to music and all that vibrant life going inside your own head. Have you noticed how many people have headphones in metro? Hey, ask why.