hi alex and welcome-
was wondering is there any way you yourself can move out? move in with a friend? split an apartment with a sister maybe? help your mom to get a smaller flat and go with her? move out with your boyfriend?
your family home doesn't sound like a healthy environment for you and perhaps consider making a plan to move out on your own steam. this may require getting a job and delaying your education, but what is the price of your serenity?
it's your parent's choice whether to split or not. it's also your choice to stay there or leave.
if you want help brainstorming ideas of how to plot your exit, we're here and listening.
sounds like a very toxic environment. i would run for the hills!
and please, consider getting some face to face support from a therapist or alanon/alateen to help you step back from your parent's marriage and your father's alcoholism.
the first step in alanon is to admit we are powerless over alcohol. it is best to leave your father's drinking and pill popping to him and take nothing to do with it. step back and detach. shift the focus to you and what you want in your life and then start making baby steps in that direction.
we're here to help. call on us!
naive