I need help because I can't keep living like this!

My mother in late 60s, alcoholic, diabetic, has gout, heart problems and etc needs help. All she does is yell at me and in my mid-30s. She is married, but my father refuses to speak up and take charge. He says he will just be yelled at and there is no talking sense into her. She needs professional help. I need help because I can't keep living like this. I moved back into their house to help them 6 years ago or so and they need help 24/7. I am holding down multiple jobs, don't even have time to take care of myself either. My mother does not leave the house. She does not even step outside. She will open the door but that's it. She is not afraid to leave, she is simply very depressed. She is overly- medicated, takes about 13 pills daily. Tonight, myself, my father and mother were eating dinner, had on a hockey game, everything was going fine, then she starts yelling at me about me not organizing her meds anymore, I told my dad he needs to do it (he's capable of doing that). I use to organize my mothers pills in a monthly daily organizer, but I didn't want to blamed for anything so I told my father he would have to do it. She then started yelling at me as I'm sitting next to hear, almost blew out my eardrum, and I ended up in tears. She kept saying she was going to kick me out of her house and I pay for the house, its not in my name, but she refuses to help any. Between myself and my dad, we are paying for everything. She constantly orders things from QVC, multiple packages arriving daily. She needs a lot of help. She does not leave the house, not even to go get a haircut. She sits in a chair all day playing on her cell phone or falling asleep during the day. She is not my birth mom, I do not know my birth mom. I'm very upset. What can I do? She refuses to go see a doctor because she thinks they are trying to take advantage of her. When my brother and his girlfriend come here to visit once a week, she pretends and puts on this fake show laughing and telling jokes and just continues to yell at me. One would not think she has dementia or anything. I've seen this with other people who have had dementia. I use to work with elderly patients. All she does is yells and screams. She does nothing for herself. My father even has to help her walk up the stairs and down the stairs, he even helps her in the shower. Yet, he refuses to get her help. She wet her bed 3xs the other week and then blamed it on me saying I poured "water" on her bed. Its so weird! You can clearly sniff out the section on the sheets with the pee on it. My dad can't smell anything and he refuses to let me change the sheets. So now, she is sleeping on pee sheets. She is up till 2 or 3am drinking. She starts drinking at 7 or 8pm. My father keeps pouring her drink after drink till 2am or 3am. I guess one could say he has a drinking problem too since he is drinking also till 2 or 3am. My mother has not even gone grocery shopping in probably 15 years or more....its always myself or my father doing that. She rarely washes her hair or uses soap. Her hair is so bad that it gets in our food and its long hair that is never washed. Her hair is so tangled and she stuffs the hair from her hair brush down the kitchen sink. She keeps threatening she is going to kick me out of the house, but how can she if I am taking full responsibility for her (trying to at least) and paying for everything? She doesn't even own a car! Need help please! Please be kind! I've been balling my eyes out since dinner time! P.S. My brother who only sees her once a week started saying some BS crap about how he loves her and blah blah blah and I get it, but she isn't his real mother either. He believes she has no issues and is well capable of making he own choices, but he has no idea what goes on! Like I said, she puts on a fake act just for him. All she ever does is talk about him. LOL. She also lies to people to get out of going places or going to see the doctors. She tells everyone my father is a firefighter and can't go anywhere LOL. She will say (like if a doctors office calls trying to get her to come in) that my father is a firefighter and he needs her and he only has one day off a week and such....its such a lie! She will also text/tell her friends that we a lll go on trips to NY, NJ, TX and other places to get out from her hanging out with her ex-co workers. I don't get it! Then, I see her old friends/ex-co workers and they ask me about the trip and this and that, what did I go see while I was in Texas and such....and I've never been to Texas! Strange if you ask me! I understand not wanting to hangout some times, but this is all the time and then I get questioned by her friends about this. My mom expects me to lie to them telling them things about how great the trip was and such. I totally do not want to lie to people about fake trips! P.S.S. I do not drink at all myself!!!