Thats normal!! If it wasn't hard for you to deal with that shows you didn't care, love her.. etc,
But having the emotional pain is normal for anyone whos in your situation.. It just takes time.. Thats going to be your cure.
Build yourself back up, Cutting things off with a partner is emotional anyway.. things get hazy in a relationship.. It is your choice remember.. Theres a reason for you wanting to end this, Thats what you have to think about..
Are you 100% sure about this? After yr done helping her move her stuff, You will be enjoying your own company for a while.. try to take your mind off it, go out have fun and very soon you'll eventually feel better..