I agree, it is not wrong to crave sex, it is a natural human desire, but it can also be a big red flashing signal that some thing is wrong emotionally if you are feeling like crap after the pleasure is over.... please look with in yourself and see what you are using to the sexual pleasure to numb or cover up.

Layman's Term:
You are using Sex as a Drug - to hide the pain / wound... and once the drug is over you need more.