AIO I'm a hostage and I want to kill him

TW: bad english some slurs and abuse and idk

I am 20 yo (context:I am from KSA,afab,probably transmasc). 14 months ago my dad logged into my insta account ('my' number is under his name) and he found texts between me and my then gf. We were together for 8 months and in these dms she used ('He',My chosen name,and masc words like man or boy). What's worse was more intimate stuff, he now has files on his phone of pictures of hers and mine that he has no buisness owning,but still keeps as blackmail. I was pulled out of college after that,I was doing so well that I had profs promising to recommend me for scholarships abroad for my Masters later. Then was locked in a room for weeks only coming out twice a day,I had my period and had to just endure being soaked I hat to pee in a trashcan more times than I can count,the windows were drilled shut. I slept on the floor and had one hunger games book that I smuggled in on a bathroom break that I kepr rereading (not fun, had to watch finnick die in my head too many times now). And until now I dont have a phone and not allowed to use wifi and obv cant go out or study or work or own money or live in general. Sometimes i'd get hit but not too much since im taller than him and my mom now. For a good while I understood him we are muslims we are arab he is conservative and everyone told me how kind he is for not killing me on the spot. But after a long time It was too much it's been too long I cant live like this im dying inside I thought by 20 i'd be free but im not. I don't fantasize of going for a walk or getting coffee or having an exam anymore, I keep thinking about murdering him somehow. I know I wont im too weak. But the thought of shooting him taking his eyes out or pour something boiling on his face is the only way I can sleep at night. I am tired and desperate and pray for death everyday. I'll answer anything and take anything you's offer. I'm using a laptop behind their back rn.