Was I sexual assaulted?

When I was about 10 years old I would go to my best friends house every Wednesday she was very boisterous and playful and we had so much fun together. As we both got older she began doing things that made me a little uncomfortable like going under the covers when we had a sleepover or kissing me, at first I thought little of it but eventually things progressed into her laying on me and touching me in places I did not want to be touched I would always tell her to get off of me but she wouldn't and I would have to use all of my strength to push her off. I became scared to go to her house and would only go if I had other friends with me. I want to know if I'm overreacting or was this really sexual assault?