Many people annoy me, I feel your pain. Is it something specific this person does? Usually if someone that annoys me is around a lot, I just keep my distance as much as possible. Do not engage the person in anyway. Keep communication to the bare minimum. Just say Hello and go stand somewhere else. Don't be his friend on Facebook. That helps tremendously. Don't answer texts.

Though, I am in therapy for unreasonable anger at people who annoy me, among other things. Maybe you could try to look at it a different way. If he's doing something offensive to you, then go ahead and mention it to him in private. Otherwise, just try to think of him as a person who is having a hard time fitting in. You don't have to be his friend, but you could be a silent supporter.

Good luck with this,
Amy