Help needed with getting away from abusive toxic parents who stole my passports

My parents took my passports and theyre holding me hostage and im a legal adult and dont know what to do

My parents took my (F, 21) passport. So recently i had to drop out of my medical school in malaysia due to personal reasons (mostly caused by my parents) and i stayed at my friends place in the US for 6 months but then they tracked me down and found me and basically forced me to come back with them to Sri Lanka (thts where my family lives at the moment) Ive been applying to new universities hoping for a transfer and such, and my dad has been too, and ine day he asked me to bring my passports because he needed to take full scans of them to send to a university so i gave them to him and didnt think much about it, and then when i asked for them back later he refused and they just wint give it back , because they want to prevent me from leaving them, theyve always been toxic and controlling and abusive so this isnt surpising. Idk what to do now, im in Sri lanka theres no laws like there is in the US, and im basically helpless any help on what i should do now wud be nice (they took my US passport and my Sri lankan passport, im a dual citizen, i was born in the US but in grade 6 we moved to Sri lanka and now ik its because my parents can get away witj any amount of abuse unlike in the US ) And now theyre saying that they wont send me to a university cz its a waste of money and theyll marry me off instead and have me do the household work until then. They have also threatened to take my phone and laptop away so ive been really careful about that. I want to get away, run away and go back to the Us, i have a friend whos willing to help me and let me stay at their place till i figure things out. The problem is getting out of the house and getting a new passport. Ive made a post before and everyone told me to go to the Us embassy(us consulate). I cant set an appointment or call them cz i cant use my phone for calls.If i just run away from home and walk into the us embassy will they take me in? What if replacing the passport will take some time like several days, would the embassy let me stay there? Because once i leave my house, i will not be able to come again no matter what thts for sure. Im also scared about them coming to find me the second they notice im gone, theyll be waiting around airports or try to track me down somehow, how would i deal with this? would i be able to have some kinda security accompany me to the airport? Another issue is i dont have any physical cash on me and passport replacements need it, i do have cash in my bank account (BOFA) but i dont know if i can withdraw money here in Sri lanka so.And if i do end up getting a replacement passport and fly back to fhe us, would there be a issue leaving sri lanka since i dont have a sri lankan passport? Any help or advice on what to do would be great, especially if you're someome who knows these things well. I am really scared but if i do wanna escape i want to be sure of everything i can do to leave and i dont want to regret it or make things worse for myself. Note- i do have my social security card and copies of my birth certicates etc, i also have a copy of my passport that they stole.