Overthinking. Anymore. please help!

Hi my problem is that I think a lot about everything. A week back i was watching porn and I accidentally switched on homosexual video and later fantasized about it. Does that mean that I am bisexual. In reality I am not attracted to men.Plz help me out with this bcoz it is affecting me a lot. It's been a week but I am not able to get out of it. Nowadays I have even started questioning myself and I try not to talk to men. There is always some strange feeling in my stomach whenever I look at men or watch them on TV because I keep on thinking that am I attracted to them. Am I suffering from bipolar disorder. Because when I am with my friend i feel good but after leaving them i again start thinking about the same problem. Nowadays I feel that I am not attracted to girls and my sex power has also gone down because I don't get aroused anymore. Please help