I'm thinking about cutting off one of the closest people to me.
Why would you want to cut ties with them?
I don't think they can handle me anymore.
You may feel that way, but are you sure they feel that way? You can't speak for them and they may really like you. They don't deserve such betrayal and you need to think harder of how they will feel when you suddenly abandon them.
No, I'm going to do what I think is best.
You should try to be considerate of their feelings and ask them what they think. If you cut ties with them without getting their input, you may regret doing so later. How would you feel if a friend cut ties with you without explaining why?