Am I wrong for this?😕

Brianna
Yesterday, my boyfriend and I had car sex before I had to leave to take the bus back to school (upstate and I was in the city for the weekend). It was exactly a month since we last had sex, so the first round was REALLY good and intense. I've noticed that every chance we get to have sex, he can only go one round, like it won't go back up no matter how hard I try. I didn't even cum. When that happened yesterday, I got upset and didn't talk to him for about 30 minutes. When he asked me what was wrong, I told him that I'm disappointed in the fact that he can only go once now. He didn't know what else to say, besides the fact that it's out of his control. He asked me what I was thinking and I didn't know what to say. I got over it pretty quickly, but he was still mad, so the entire ride was quiet. He's still mad today. Was I wrong for telling him this? Did I imply something about his performance? He's great in bed, but I hate that we can only go one round. 
UPDATE: I talked to him about this and I realized that I was wrong for telling him in the way I did and for getting mad. I told him I was "disappointed", which made him feel like a disappointment and like he couldn't satisfy me. He was upset that we took this chance to have sex, which we usually don't have, and I got mad because he could only go one round, which made him feel that I didn't appreciate that chance. I apologized for making him feel that way and told him I just wanted to be honest, although the way I went about it was wrong. He's still upset, but said he's going to need time to get over it. He apologized for not being able to satisfy me the way I wanted to be. I feel like such a bitch.☹️