I'm supposed to move in with my best friend but I am going to renege.
Did something happen? Why don't you want to move in with them?
My good friend from University was a jerk to me and a party animal
I can see you are frustrated, but it is wrong to go back on a promise you made. Your friend might be hurt and will stop liking you. You should talk to them and clear things up.
It's too late. I'm going to delete my friend on facebook and ignore their calls.
Sometimes we need to move on from relationships but if this is your best friend you should at least give them the respect of having a conversation about why they are bothering you.  Moving in together can cause issues and perhaps it isn't right anymore, however deleting them and moving on will be hurtful, you may regret it and it isn't mature to act that way.