Did I make the wrong decision moving in with my boyfriend?

Me and my boyfriend have just moved in with each other. We have already started arguing and I'm already starting to doubt if we have made the right decision. 

We've been together for 3 years so thought it was a good time to move out. However he has no idea how much things cost and wastes money and eats everything and then says "well it's not yours, it's ours". 

When I ask him to do simple things like wash his cup up instead of leaving it on the side he just says to stop telling him what to do. He doesn't understand that he can't be selfish anymore and it's not just down to me to do everything. What can I do?