I feel like I was SA please help

I just started seeing this guy about 2 months ago. I really like him and we connected instantly. Weve gone on several dates and stayed at each others apartments a few times. Last weekend he was staying at my place. We live in different cities so he was staying for 2 nights. We have sex all the time and I felt very comfortable with him sexually. But the last time he we here I woke up in the middle of the night to him inside me. I told him to stop and he told me to just go back to sleep. I tried to push him off of me but it didnt work. He just said "shh I just need to do this and youre wet so you obviously like it" I started to panic and tell him to stop but he finished anyways before rolling over and going back to sleep. I couldnt sleep for the rest of the night I just cried and felt scared and violated. He hadnt shown any kind of behavior like that before. I was too scared to say anything so I just said bye to him when he left in the morning. I havent responded to him much this week and he keeps asking me whats wrong. I told him I was uncomfortable about what happened and he said its not a big deal since we have sex all the time anyways and he doesnt understand why im upset. I never told him It was okay to do that. Am I overreacting? I feel sick and dirty and I feel like I was violated. He thinks I need to lighten up. Please help me.