being left alone sick for 13hours

My fiancé knows I get sick as a dog at nights and today he decided to go out with his friends at 1PM and still won't return home after 1AM. Am I overreacting for being pissed? This isn't the first time he's done something like this and I'm to the point where I don't know what to say nude I'm so angry for being left home sick and needing him while he's out getting wasted with his fucking friends! I'm at the point where I want to leave. I don't want to feel like I'm in this alone. It's not fair to me. He should be In this with me.