I'm going to cut off my friend because of Xbox.
Can you elaborate more on why you want to cut your friend off?
He's addicted to games and is just generally not useful.
It's completely ok if you dont want to continue your friendship with your friend. There is no point to remain friends if you dont get along well.
I swear I'm going to do it.
That's fine if you want to no longer be friends with him, but if you do at all want to stay friends, then maybe talk to him about how you're feeling. If you explain that you're worried about how often he plays games, he may consider changing his habits.