There are a lot of unknowns here.
For one thing, what level is your relationship at? You called him your "boyfriend" but that could mean anything from guy you've been dating for a month or serious long term, monogamous partner.
Then you said you were drinking, so it's possible you said something awful that caused him to understandably want to back off a bit and reconsider this relationship, and did not feel like getting into it any further with you at that time.
Or something could have come up where he really did think he might have to work. Or he could have been waiting to hear back from another girl or his friends and considered you his back up plan. Or many other things.
His other actions like not always calling you back when he's out with his friends or not answering you when you asked if something was wrong could also mean different things. For ex., it could mean he feels that you call too much, or that perhaps he views the connection as not being at that close of a level or etc.
So in my opinion, he might be acting like a jerk or he might not. I can definitely see someone being perfectly nice even if he doesn't handle everything the way some people might consider the only correct way.
Moving a date from a Saturday night sleepover to Sunday does seem like a downgrade to me, though unless he did have to work. Good luck for Sunday. Please keep us posted.