NTA. You have every right to decide who you want to have sex with and in what context. I was very much like you when I was your age. At 19, I'd only slept with one person: my high school boyfriend, and I dated him from ages 17-21. After we broke up, I only slept with people that I had some kind of friendship or acquaintance or people that I was dating, which means it was in the single digits-and one of them is the person who is now my husband of several years. It's just the kind of person I am. I have never felt comfortable with the idea of casual sex. And fortunately for me, my husband isn't either. I would much rather go solo than hook up with a random person. I think some people might say it means I'm demisexual. I think I'm too old for that kind of definition, but it does fit my own experience. Good luck-you're still very young. There's plenty of time to find the right person for you.