If you believe you're gay, then that's what counts. The problem is usually that one tries to convince himself that he's not (or that at least he might be bi). In what sense are your friends making you second guess yourself?

Most gays have known we were attracted to other men since we were very young. Now, we might not have known what it was called, and it might cause us a crisis when we find out and begin to face up to the implications of it, especially if we've grown up in a church that considers homosexuality to be the worst possible sin; but my facing up to it in no way changed that I had always been this way.