Constant headlice at 36 weeks pregnant!! Pls help!!

Okay I really need some help. Any suggestions or advice. I am so lost and so so tired of this sh*t. Okay so I’m only 18 and I’m 36 weeks pregnant, literally about to go into labour within the next two weeks or less (as I’m dilating and contracting. My doctor says.) I live with my parents and three younger siblings because I was put on bed rest so had to stop work. Well I’ll start by saying we have a nice house which is always clean and what not. But my siblings are completely disgusting. They never shower, wear the same clothes for weeks, leave everything at their asses. They’re so lazy it’s ridiculous. Anyways they’ve had headlice on and off for about a year or longer now. They’d do their hair (brush through with a nit comb and get all the lice out) but they refused to wash all their stuff. I don’t know how many times I worked my ass off washing every cloth in my house, vacuuming every couch and bed, just for it to come back within a week because they never did their stuff. Now I’m sick of it. I usually never have it or when I do, just a few. Well we just tried to get rid of it maybe a month ago and we thought it was all gone, well guess what, we have it again 🙂. And they still won’t do shit. Not even their hair!!! They’ve none for about a week and haven’t done anything. I feel like completely breaking down honestly. I can’t stand this anymore. So now I have to wash all my baby’s stuff even tho she could be here any minute. I did my hair and will continue doing it obviously. Also they have extremely thick and long hair to the point that it takes around 6-10 hours to go through their hair and they refuse to cut it. I have very short curly hair. My parents cannot do anything because they are not allowed to parent according to cas. And if they do try to make my siblings do anything at all they will be charged. This isn’t bullshit, I know it sounds like it but it’s too much too explain. So my parents can only tell them to do something and hope they do it. I need some advice. What should I do?! My baby can not have headlice, if cas finds out she could be taken away. I don’t know how I’ll be able to make sure she doesn’t get it if they don’t get rid of it. Should I lock them out of my room? Would that even help? How can I make sure I don’t get them again? And maybe how can I make sure they don’t get into my room? I tell them to stay out but they don’t listen and they even come in while I’m gone. I can’t move out as there are no houses or even apartments for rent anywhere near here. Please I’m begging for some help I can’t put my child in this situation but I also can’t make them do their stuff..