Lowcost hobbies?

I'm not very rich. I can't really afford hobbies, I can only really surf the web. I can't get a job because my parents are in school and also working and I have to babysit my little siblings. I can't drive anywhere because again, my parents are always busy and running in and out. I feel so stuck. I don't go outside for days. I feel distant from my family. I go outside twice a week with my boyfriend and it's hard not to get codependent. He takes me out and buys me nice things and gives me infinite love. And I know my family loves me too, but it's gonna be like this until they finish with university. It's getting really hard. For the past few years I've just been going to school and then napping until really late and laying in bed all night and repeating it. I feel empty and sad. You can only surf the web and watch movies so many times. I'm tired. Whenever I hang out with my boyfriend's family I feel envy. They're really close. And comfortable. And they invite me and hug me and treat me well. I feel like an ungrateful shitty daughter. I just wanna move out when I turn 18. Not only this, they're somewhat strict. It's tiring. I want to get a bike or a skateboard so I can go places but they said no.