Sexual abuse? Long story

I don't know how to really start this but all I'm asking is for someone to listen and tell me I'm not weird. I'm only 15. When I was nine, I met my best friend. Her name was (name change) Anne. We were always hanging out together and while we hanged out sometimes she would say sexual stuff. Like talk about penises and blowjobs and humping. I didn't really know what that stuff was but since I was naive I kept listening and talking about it. It kind of made me uncomfortable but since it was a new topic it was interesting to me. Then, things progressed. She started talking about lesbian sex and how girls do it and she wanted to demonstrate it on me. In her room, she started to feel up my breasts and would touch my genitals with her hand over my clothes and would ask for the same back. Still, I was so naive I didn't realize that this was not normal. Also, I become more uncomfortable as this occurred since she started to ask me to hang out more, meaning more sessions. Then at recess, she started asking me to hump her and moan. I didn't really want to but I gave in. We started scissoring and she would tell me stuff like "does that feel" good? and "you like it?". We would do this every recess and the hangouts started to get longer. Eventually fourth grade ended and since we got different teachers, she never talked to me again. Everything stopped. This experience didn't really hit me until recently; I guess it was my mind's coping mechanism to block it out. Now, I just feel so sick. Like how could I have been that naive? It made me uncomfortable yet I still did it. Now, Anne is really popular, drinks and has sex with guys all the time, and the worst part is that I see her all the time and I don't know if she remembers; if she's blocked it out like I have and it sickens me how someone could do that to someone else. Now I'm afraid to have sex and I'm questioning my sexuality and I'm just so confused. I always felt like I was straight but like this make me wonder. I just don't know what to do. Am I gay? Was this actual abuse? How can I get past this?

How can I be comfortable in the future having sec? I don't know.

Thank you so much for anyone who has read through all of this. It's nice to know someone will listen.