I think I may have feelings for one of my best friends. What the hell do I do?

Ok so just for some context, I'm a 16 (17 in july) year old guy currently finishing up grade 11 in highschool. I have a small group of friends that I've known for a few years, but outside of that I'm pretty bad when it comes to socializing. One of my friends, I'll just call him "Alex" for now, is just so nice all the time. Recently, I've just had really strong feelings for him. At this time, I really don't know what to do about it, as only one of my friends actually knows that I'm gay. I'm just about 100% sure none of my friends are homophobic/etc., but even if I did ever let Alex know how I feel, I don't know how he would take it, or if he's even gay at all. What should I do?TL;DR: I think I love one of my friends, but have no idea what to do about it.