Well, there's two ways to look at the soccer team situation. You could stay on the soccer team and listen to the constantly negative attitude of your teammates and thicken your skin when it comes to comments like that, as well as having your opportunity to peek at your friend without a shirt. Or, you can remove yourself from the situation by quitting said soccer team and also removing yourself from a situation in which you'd be able to see your friend shirtless.
I've been down this road before, and I know it's difficult, but if I had to choose one, I'd choose the second option I gave you. When you feel uncomfortable in a situation, you have every right to get out of it, and while I do understand that you may relish the idea of checking your friend out in the locker room, you're better off abstaining from that. Time and distance will get rid of that longing feeling you have. I've been through the "best friend is straight but I still like him" phase, and honestly all I did was distance myself from scenarios that could strengthen that attraction, and finding distractions so I wouldn't constantly be thinking about him. The sooner you realize that longing for someone who can't return the affection is worthless, the sooner you'll get over it. And let me tell you, what you think is a crush, is very minor. The guy I refer too was acting gay with me and I was genuinely convinced for a time that he was bisexual and I thought I had a chance. I doubt you're in that deep yet, so getting out of this won't be challenging.
The one thing I cannot help you with is helping with the homophobic attitudes of those around you. Most people who have the idea that homosexuality is wrong/a sin are too thick-headed to understand any sound argument from the opposition. It sounds awful, and I hate to recommend it, but your skin will thicken. And you will find people who will accept you for who you are eventually. And when you are able to be open with them, it's a wonderful, freeing experience. You can get through this, trust me. And until you can find those who are willing to accept you, just know that everyone here should be accepting of who you are.