Did I cheat on my partner?!

I was talking to my partner (on the phone) this afternoon and he starts accusing me of cheating on him. He says that what I did was wrong and he's mad and upset. Apparently I cheated on him🤔

The reason why he's accusing me of cheating is because, I told him that while I was on a flight (on my way to see him), I sat next to this guy and me and the guy never even talked on the plane. We were both tired and I found myself waking up with my head on the guys shoulder. I didn't mean to intentionally do it. I was just very tired. I fell asleep and the guy next to me was too.

While I was trying to explain to my partner how tired I was on that day, he starts to tell me off and starts saying that it counts as cheating and he has every right to be mad/upset because I had my head on another men's shoulder. To go into more details about my relationship. My partner and I are in long distance relationship. We've been together for over 8 months now. Everything is going well so far. We visit each other every month but I have noticed that he does overreact on certain topics. He's not clingy and he gives me space. We both work and we only get time to talk after work. We live in 2 different states from each other but the same time frame.

Anyways back to the little disagreeing me and my partner had. While he was trying to tell me off, I told him to hang up because I just couldn't stand him blowing things up to proportion. Anyways he hangs up and hasn't messaged or called me since...when we normally sleep on call every night🤷🏽‍♀️

Am I in the wrong for not being understanding and did I cheat on him?! HELP?!!