I think you mean you were convinced heterosexuality was the "right" sexuality? I think a lot of us are raised that way. But it depends truly on the culture and time. There have been many societies now and back in the day where homosexuality was viewed as normal or at least accepted. Granted, many societies dominated by Christian idealogy are not accepting and teach children from a young age that girls marry boys and boys marry girls and anything else is WRONG.
I think you should be able to choose for yourself what you feel is right or wrong (obviously within reason, i.e. no hurting other people LOL)

You're young! There's probably much about the world you don't know yet and have not experienced. As long as you're open to yourself and others you really can't go wrong! Good luck!

i learned it like this: sexuality is like food.... everybody's tastes are gonna differ. your best friend might LOVE macaroni and cheese, but you hate it. does that mean you are wrong? no. does that mean your friend is wrong? no. it just means that you both like different things. it's much the same with sexuality. your sexuality is YOURS. own it. don't let anybody else try to influence what you believe. figure it out for yourself. that's the best part of the journey, knowing you got there by your own two feet :)