I got drunk one night at a party, and this hot girl. I thought it was a girl, pulled me into the back room and gave me a blow job, we went all the way. When I woke up, I saw her in the bathroom. It was a GUY!!! She was peeing while standing, am I gay

Anyway, if you thought it was a girl, you're not gay in the slightest. Gay men don't find girls attractive sexually like that!
If you really think you could be gay, it should be easy to tell how attracted you are to guys and how attracted you are to girls if you remember it's your choice who you sleep with. Then decide if you want to do girls or guys or both (eg. what you're comfortable with, for most gay guys it's like a natural fit to do it with a guy). But wear condoms if you do it with a guy because of hiv risks.
and btw thts hawtt