Firstly, awesome reference to It's always sunny in Philadelphia
Secondly, get the fook off Facebook. You are looking at the highlight reels to other peoples lives. It will obviously make you more depressed.
A lot of what you are feeling is made up by you own mind. That's why text is a terrible means of communication. You can't maintain a relationship over text. Call the dude if you want to speak to him.
I don't think you are gay. You just formed unrealistic expectations of what the friendship was. It happens a lot to introverts. They "imprint" on one person. I also don't have a best friend but I do have people I can talk to. You need to find people you can talk to. It can also be family. Most people are in the same situation these days. There is nothing wrong with you. Society is just that way at the moment.
My new myBB best friends, what is wrong with you?