What is "Odi et amo. Quare id faciam forte requiris, nescio, sed fieri sentio et excrucior." in english?

I hate (odi) and I love (amo). Perhaps you ask me (forte requiris) why I do this (quare id faciam). I do not know (nescio), but I feel it to be happening (sed fieri sentior) and I am in agony (excrucior - literally 'on the rack').