Was I assaulted?

This morning my boyfriend and I were sleeping and I was so exhausted. He had woken up before me and started touching me (sexually) and by that time I was still and sound asleep (I did not touch him at all) he then took my underwear off and his all at once next he had flipped me over on my back, and asked if “can we have sexy time or are you asleep?” I responded by saying “I’m not tired” (obviously I was) and had my eyes closed not moving one bit & next thing I knew he was having sex with me. I had woken up and he had already finished and I was shocked I said you didn’t think enough to get a towel and he said sorry I was just thinking about you and I responded or you were thinking about yourself then he said you were half asleep you didn’t know I was inside of you and I just became numb. Why didn’t I speak up? How hard would it have been if I just said no!? Idk how to react or what to do..