how to stop the parents from destorying everything

so i got this dad who takes alot of meds and hes up and down and spiraling and my mom whos siting there going u need them but they fight alot and threathen to diviorce all the time my dad just spirals into episodes i keep telling him to listen and chill out i cant stand seeing my younger ones get hurt hes not in full adherance to whats going on but its not his fault he had some bad episodes and i think the med hes on effexor is a anti depressant is makeing him weird and plz help me make this come to togther i want it all to be normal

anyone