Mother-in-Law Problems

Bailey
So basically, my boyfriend (Seth) and I have been living together for six months. Seth inherited the property from his late Nana. However, due to age complications, it is in an administrator's name until he turns 21. Said administrator happens to be his mom, Robyn. Robyn had a huge life change (she brought upon herself) and lives with us (along with his Papa). But legally we cannot kick her out until my boyfriend is 21 (I'll explain shortly why we all want her out). 
Papa is physically limited due to his age and health. Seth works a full time, labor intensive job. I was recently hired, but have been unemployed for several months due to health. I have severe anxiety, asthma, and fibromyalgia. So at times, I can be very physically limited. Seth has a very strong dislike for his mom (for just about everything she's done). For the longest time I didn't understand why, but these last few months have shone light in some dark ass places and now I know why. 
ANYWAYS. 
Robyn does not work and hasn't for about three years. Her day consists of sleeping in super late, sitting at a table all day making crafts, playing on her phone, and eating, and then leeching off her boyfriend and manipulating him to take her to a fancy dinner. And the occasional begging of money from Seth. Keep in mind she lives here rent free. 
Well, I do most of the housework, which adds up fast (mostly because she's a super slob). This is incredibly strenuous on my health and has caused serious flare ups from the stress. She refuses to help at all and gets super rude if I say I need help. She expects me to keep everything clean and bitches at me if I "slack off" from being sick and physically unable to do anything. She also expects me to drive her into town whenever she wants. Whether it be for a doctors appointment or a whim to guilt me into buying her stuff. And she gets super petty and rude if I refuse, to the point where she's gone to Seth and talked shit about me and that he needs to kick me out etc. And don't even get me started on her little shit stain of a dog, whom she encourages to shit/piss in the house (and gets upset when I say that she can clean her own dogs shit up since it won't go to the bathroom outside). The same dog who has infected my dog (Ty) TWICE with worms, because it shits in the house and like any curious dog, Ty gets into stuff. 
She has health problems, however, they were all preventable and are now manageable (since it's too late to prevent them). And she goes to doctors appointments (that are completely free) and is on a shit ton of meds (that her boyfriend pays for). At first I didn't mind taking her to her appointments cause it seemed like they were making progress etc. But when they told her she was diabetic (due to being obese), she refused any life changes. This opened a door to me eventually seeing she does not care for her health, she actively seeks drugs and enablement, and that she is straight up fucking crazy. 
She constantly interrogates me and Seth about everything (to a point where I have the urge to punch her the fuck out and he gets so irritated he leaves the house for a few hours). And she intentionally crosses barriers CONSTANTLY. It could've be accidental/coincidental once or twice, but she intentionally does this shit. Like randomly bursts into me&Seths bedroom (even when we are clearly mid sex) or trying to sleep or change clothes etc. She also NEVER lets us have alone time. Im sorry, but romantic Valentines Day dates are meant for me and him, not her. She tried to go with us and I pulled Seth aside  and said something to him (whispering) and she eavesdropped (another one of her annoying ass habits) and found out and fake cried to try and guilt us into bringing her along (and I put my foot down and drew the line there). I straight up told her that if she wanted to go on a V-day date so badly, to call her own boyfriend. And this is constantly happening with everything we do. She invites herself along and expects us to pay for everything. She constantly tries to cause problems between me and Seth and push us apart (which thankfully has not worked). However, we fight about her a lot (which she usually eavesdrops on). 
She also happens to be a hoarder (while I happen to be relatively minimalist and clean along with everyone else in the house). Like to the point the fourth bedroom (which use to be empty and was potentially going to become Seth's home office) is filled to the brim with her shit. Totes and totes filled with useless junk. I'm sorry, but who needs 100+ kids toothbrushes? Or perhaps three totes worth of stuffed animals that are moldy and Seth has been trying to throw away for ten years? Or maybe the twelve totes and clothes that she's outgrown for a LONG time and are too torn up to wear anyways? And not to mention her TERRIBLE hygiene. I'm sorry, but if I can SMELL you from across the room, honey you need to take a shower and burn your clothes. Like I can't stand to be within five feet of her. Even after she's "showered", she still smells putrid. Even my gross teenage brother smells better than her. There's times where she's been in the car with me and refuses to roll the window down and it has caused me to gag so bad that I've had to pull over to throw up. 
ANYWAYS. Well I told Seth that as soon as I got a job, things would need to change. As I would not be in any way able to work AND do everything around the house. Well I did get a job. Seth doubts that saying anything will bring change. And if I don't clean, the house will probably go to shit and decrease everyone's quality of life (except hers cause she's a slob and doesn't care). So I'm about to snap. And she found out about my job and got mad because she asked if I could take her to her appointment even though I said I have a shift that morning and that I can't take her 🙄 and even though her super nice case worker offered to give her a ride. I've been so patient with/about her, but I'm losing my patience so fast. I'm at my wits end about it all and me and Seth have no idea what to do anymore about it.