I feel kinda bad for you, because I totally see how it looks very crappy and unfair from your POV.
But sweetie, take it from someone older, there is so much negative, bad, evil out there, in so many forms, that I totally get why a parent would want to be very overprotective of you/their child, especially a female/girl.
We've all been your age before, and we all been there/done that. Sex, alcohol, weed, etc. STDs, cutting school, etc.
I have a young relative that I worry about/for, also. So I get it. Totally. Both sides. I know that doesn't make you feel better. The only thing that I know is true is that you will thank him later, when you're older, grown, mature and turned out an awesome young lady... that he saves you from all of the **** that girls your age go though: sex, alcohol, drugs, pregnancy, STDs, problems at school, etc., etc.
I wish I could say something that helped you feel better. Some insight that would help you "get it." But only time, age, maturity can do that for you.
Don't worry about what "other people" are doing on social media. Social media is NOT what you want to worry about. Forget about everyone else. Worry about yourself, your future, etc.
Feel free to reply, ask any questions, etc.