Am I gay?

I don’t really know what am I: gay, bisexual or straight.So basically I thought I was romantically straight, sexually gay. Every time I get horny, I start watching gay porn and it really turns me on, but after I finish I feel disgusted at it. That doesn’t happen when I watch straight porn, but I don’t enjoy it as much.Also, I had sex with another man for the first time yesterday. And I didn’t enjoy it. I came quickly and after that all I could think was “I want this to end. I am not gay”.