Help Cutting urges while living with parents still

[ilovepsyschonaut4]

I have a early birthday so I'm going to graduate high school when I'm already 18, meaning I'll still be living with my parents until I do eventually graduate and possibly even after due to how expensive things seem to be nowadays. If my parents found out I was cutting myself, could they put me into an institute without my permission or no since I am a legal adult?
(I'm sorry if this is the wrong thread I'm still new to the site!)