Watch porn, (not gay porn). If you do watch gay porn then block all links to gay porn on the internet.
If you look at a man and think "Hes sexy", Try to control yourself and say "Eww ".
I have always thought "What if I am gay but I don't no it yet" I would never think about become gay or even trying it, but I do understand what you mean, and I think every one had atleast thought about it...
You could try conversion therapy, although it has caused quite a bit of controversy with gay groups. There is no 'medical solution' to homosexuality though.