First of all, I'm sex addict and I got introduced to anonymous sex a few years ago in high school, and ever since I never had an emotional relationship. I was mainly into hookups and one-night stands. I've never used a condom before and never had protect sex. I don't know how many people I've had sex with. But a rough estimate would put that number around 700. (I have sex about 3 to 4 times week, each time with a different person. That means 16 different people in 1 month, and and around 200 each year. This has been going on for about 4 years now. I first started having anonymous sex at 17 and I'm 21.) I've never thought about getting STD or pregnant before. But at the annual health checkup, my doctor asked me a bunch of questions about my sex life, and he got really worried.

I have practically no knowledge about HIV, and should I be worried?

Please help, I'm kind of scared.