Feeling behind...

I’m 17 and I feel like everyone around me has achieved major life milestones way faster than I have. Most of my friends except for 2 have lost their virginities and I know it’s stupid but I just feel like they’ve all just had much more life experiences than me. I didn’t have my first kiss until I was 16 and I’ve heard that the average age for that is between 10 and 14. I’ve never even had a boyfriend or girlfriend before and I feel like everyone I know is in a relationship. I just feel like everyone is doing so much better than me. Does anyone have any advice for not feeling this way??