i keep digging myself a deeper grave.

my life is slowly crumbling around me and theres nothing i can do, for the last 6 years my life has been at a steady decline, my parents refuse to get a divorce in fear of shame, yet my siblings and i are the ones that bear the consequences. i relapsed into self harm about a year and a half ago and not a single person has noticed, the only friend who i expected to understand, or even notice is leaving for college two continents away in 3 weeks and i cant handle it. I am not a military child, but i do go to school on a military base, which means that every three years all my friends leave and im never allowed a moment to mourn before my new one are gone too. i gave up on having friends a while ago and not in a depressive way (sorta) because i still have mutual friends in different grades and such, but i never have anyone to really talk to yk? and i havent hung out with anyone in nearly 2 years now. dont get me wrong, i do enjoy being in the background to a degree, silence has always been my preferred state, ive gone mute for days at a ime with no one ever noticing. ive had suicidal idealizations before, but havent ever truly considered it an option, i have sworn to myself that the second i turn 18 im leaving for college somewhere in the states most likely (i live at a us military base in the uk atm) i think i wanna go to IU, but as soon as i find my footing, and have a stable income, im gonna check myself into a mental institute, ive had some seriously dark thoughts lately but my parents dont believe in the mental care system, but my friend(the one leaving a few weeks) went to an institution when they were 14 and said it turned their life around, and idek im just a kid rn, im 16 but i really want to escape, im a glass middle child to 3 disabled siblings, and a child carer to my mentally unstable parents and i am wiling to take any escape necessary to leave this hell hole ive been raised into, but theirs really no safe way to escape, other than simply biding my time.