Is this sexual assault?

I was in a relationship when i was 14 (he was 15) and we were kissing then he took out a condom and i was ok with it, but then he put the tip in and it hurt too much for me and i said to stop and i dont wanna do it no more. He looked at me and literally said “We’re fucking I did not open this condom for nothing” and went on top of me but i slid away from him and ran in my bathroom. Is that sexual assault ?