Going through breakup - lost

My boyfriend and I of 2 years had a fight yesterday nothing major I left his house and figured we would both cool off and make up. Well he went to a party we were supposed to go to together last night and he's still not home I didn't text or call him until tonight he told me to stop texting him I was ruining his evening and told me to GO AWAY I just don't understand how someone can change overnight? I'm lost and don't have a test left in me