Sexually confused reassurance?

How cam I overcome my sexual confusion dated girls for my whole life... Then I remember things went downhill when I was playing a question game with this girl who asked me if I'd had a gay moment... :S and my exams were approaching in like a week like 9 of em which was bad. I'm still attracted to girls but why has this suddenly cropped up? Is it hormones, adolescence, exam stress side effects? why do I keep getting intrusive homo thoughts? All I want is my life back the way it was 3 months ago b4 all this started I hate feeling like this is there a therapy, remedy, that will clear all of this from my system? How can I get back to the way I was b4 ? I want a wife and kids I love women but why has this happened? How can I get back? This is driving me insane and life is just tolerable I don't enjoy it at all can u reassure me I'll get back please? Much appreciated x