Feeling lost in flashbacks

TW—It’s been four years… I don’t even know what to call what happened I don’t feel like it fits in a box? I was 17 (almost 18) and he was 24. He was my best friend’s older brother, while he was serving military overseas we started talking and he quickly made it sexual saying he always fantasized about sleeping with his sister friends and there was so much manipulation of saying “you might have a chance if you give me your virginity” and other statements along that line. When he came home 7 months later he told me her wanted to take me on a date, so I skipped school and he picked up and took me to his house. He told me I had until the count of three to pick a room or leave and things progressed from there. He asked if I was sure and I said yes out of fear of loosing him, but I also hesitated and had my legs clenched shut until he pushed them apart. I’ve thought about this every single day for four years, any guidance would be greatly appreciated.