12 y/o who is probably gay.

I am a 12 y/o boy who thinks I am probably gay. I liked girls mostly in my elementary years, but now that I'm in middle school I've taken more attention to guys than girls. There's an 8th grader in my school that I feel really attracted to, and I become nervous any time he talks to me. I recently went with my family to see The Greatest Showman (great movie btw), and before it started, a trailer for the movie Love, Simon showed. My palms started sweating immediately and I was slightly shaking. I really don't know how to feel about all of this.