You were born gay because that's the hand you were dealt. You were born male, you were born so-many-feet tall, you were born to these parents, and you were born gay. These are givens. These are things that are unalterable, and so it's best to simply accept them.
But in the case of being gay, I want to hasten to point out that it doesn't have to be some huge albatross around your neck. I'm gay. Everybody in my life knows I'm gay. And my life kicks everlovin' ass.
Would life be easier if you were straight? Perhaps. Mainly because you wouldn't have to go through the "coming out" process. But life would probably be easier if you were extremely attractive and ungodly rich, as well. But you (presumably) ain't, so you make do with what you got.
And yes, gay friends can have straight friends. I haven't sat down to figure it out, but I'm pretty sure my straight friends outnumber my gay ones. You know why? They don't care. They don't care what I do in my bedroom. They like ME, not my sexuality. I'm assuming your friends are the same. If I were to ask your friends "So, why do you hang out with TheIt?", none of them would say "Because he's straight." They'd say "Because he's fun" or "because he always makes me laugh" or "because he always listens to my problems" or whatever. If they like you straight, they'll like you gay. And if they don't, honestly, fuck 'em. No friend worth the word is going to let something like sexuality disrupt a friendship.
The key is not to bemoan and wail your lot in life - it's to make yourself the best goddamn life you can, given the cards you're dealt. I'm gay, klutzy, awkward, shy and unattractive. And I'm partnered, have plenty of friends, and love my life. It IS possible.
First step? Well, let's see if we can get two steps in one. Accept it. Look in the mirror every day and say "I'm gay". And say it until you can say without sounding like you're admitting to murder. Until you stop getting that queasy feeling. Until you say it the same way you say "I'm six feet tall" or "I'm 20 years old". Until it's just a fact. Because that's all it is - a fact. A datum. A piece of information about you. It's not a problem, it's not a disease. Your problem isn't that you're gay. Your problem is that you can't come to grips with the fact that you're gay. So keep working on that.
And secondly, LOVE being gay. When you fantasize about another guy, don't do it shamefacedly. When you look at porn and/or jack off, don't do it with a furtive eye and embarrassed look on your face. OWN it. LOVE it. Go whole hog into it. Think "Yeah! This guy's fucking HOT, and I'd love to bang him/be banged by him/whatever-you'd-like-to-do-with-him." And post-orgasm, STAY feeling good about it. Because there's nothing wrong with being gay, and it feels fucking great to live according to your programming.
Lex