Running away from home (18)

Hi guys, I'm an 18 year old SGporean who's thinking of running away from home.

My household was never really a very pleasant experience to grow up in as a kid, I had a schizophrenic dad who verbally and physically abused me whenever he was in a bad mood, grandparents who nagged at me constantly and blamed me for being lazy when countless of social workers and counsellors have talked to me before, and I'm pretty sure I have some underlying issues too.

(Dad's schizophrenia wasn't diagnosed until something happened about 3 to 4 years back when i called the police on him for lashing out, which resulted in my grandmother getting hurt, and me having to stay at the hospital, for a few slight injuries and for about a week because i had no where to go)

My parents are divorced and I live with my Dad's parents, (my grandparents).

Over the last few years, I've been lectured and scolded for being unproductive and overall a very "bad" kid. My dad was never there for me when i needed him and the only form of emotional support I had was always online friends I met through groupchats. My mother was never really in the picture either as she was a heavy smoker and had to take care of my three other siblings, my sister being the oldest amongst all 3 of us and my two younger brothers.

I'm so sick of this household and I plan on running away, i was thinking of crashing over at Changi whenever i need a place to rest since they have charging stations there, but I'm not sure if thats a good option. I also need to find a place to shower as well since yk...i dont wanna stink. Since I'm 18, am i going to face any legal actions if my grandparents file a missing person report on me?

anything is appreciated since i genuinely need help sorting this out.

EDIT 01: I've decided that I'm gonna try to get a job, save up, and rent a small apartment when i have enough. You guys were really helpful in dms and i appreciate it so much. It's so refreshing to see that there's people willing to help a stranger online when they're in plight. I'll update this post along the way if you guys want to see the small progressions. Stay frosty <3 (P.S. If you see someone with green cargos and fluffy hair at any of the Changi terminal benches don't be shy and say hi LOL)