16F and not one single friend

It’s currently the summer holidays and I’m not joking when I say I don’t have one single friend. I’ve tried to make friends at my college open day, I added people on Instagram, some didn’t even reply when I messaged them and I asked one if they wanted to hang out and they made up a lie that they were busy :( I’m a really nice girl and I feel soo crap when I see girls hanging out together in public, I try to not let it get to me and just enjoy my company but sometimes it really gets to me, I feel so deprived of social connection and I don’t know how to make friends or how to maintain friendships. I signed up for a group theatre play with people my age at the beginning of next month and I really really hope I can make atleast one decent friend there, and I really hope I can make friends when I start college, I hate being alone so bad. I just needed to get this out as all my family members think I have friends so I can’t tell anyone how lonely I am. Thanks for reading.