How can you determine how many caregivers a person should have?

to be more specific, in my case the patient is a middle-age female who suffers from multiple sclerosis, progessive-relapsing. she also only has one arm so transfering her own self into a wheel chair is a no go. so she is completely bed bound and has no mobility from chest down, her one hand is beginning to weaken now so she is not able to do much at all. she has pretty much no family, a brother who lives a state away and does not visit and a cousin who visits very rarely, she had quite a few friends but once i entered the picture they all scattered after promising me wednesday evenings off and days off as requested. i am of no relation to this person, i live in her home with my fiance and two children (4 and 8), we are a young couple (25 and 26). this woman has one dog who pees in the house and 4 out of control stray cats who destroy everything and pee in the house. she cannot afford to pay all her bills, medical supplies, personal needs, and then to care for 5 animals on top of it. so im now in debt from having to pick up the slack which it was either dont pick up the slack and have our power shut off along with other utilites or go broke paying what i can. she has only one person that helps out and by that i mean comes over and gives her a very small window of company and if i need help with finances (not actually pay them just help call for extentsions n such). she will sit with her for a few hours when ive had things to attend but this has only happened a hand full of times, in a year ive had only 4 days off and that was only because she was in the hospital and even that was not really days off because i was having to go to the hospital or have her call me constantly throwing a fit about her nurses or not getting her way. if she does not get her way she will treat you like crap, she yells at you, talks crap to you. basically what im getting at is that i have requested a day or two off every other week or even once a month, i was told that maybe i was not cut out for this job since i wanted time off. the amount of things i have done for this woman way exceeds the basic care required. im talking redid her entire house which was slammed full with stuff (horders), raised money for her by doing a huge yard sale/bake sale, raised money for her by doing a gofundme, i have gotten her up and given her make overs and then her own little photo shoot, ive set her room up like a spa and served her fruit, cheese, and crackers with wine, and so much more to try to make her happy but nothing makes her happy. all that is fine with me, what is not fine with me is her talking about me behind my back as if i do absolutely nothing for her and then getting chewed out for not doing enough or not doing things that are not even my responsibility. or being told im not cut out for the job because i want a few days off a month. ive cared for 5 patients in far worse condition than her and would do it for 40 hours straight, no sleep, no break, non stop 40 hours. never complained, was my favorite job, loved it. so i can def handle this but im human, i need time for myself. whenever i say im tired or i need a break or im not feeling good thats when she comes up with even more things for me to do so ive started to shut my mouth. im constantly caring for her and if im not then im constantly cleaning up after these animals. ive tried telling her one friend that helps that im not being a bitch or anything of that sort and what im asking is not unreasonable that i am actually a very sweet person who does not say what needs to be said when it needs to be said that i just bite my tounge that she is crazy if she thinks someone else is going to come in here and be ok with what all i deal with. ive had over 500$ worth of my belongings destroyed by her animals but she refuses to get rid of them and thinks im just being a bitch. i just want to know what someone in her condition should have as a cargiving team, is it really just one person or does she require more and is it fair for her to expect me to care for 5 animals that are not mine and that are destroying my things, her things, and this house which freaking stinks to high hell. its not sanitary and its not right that my kids have to live in it. i feel like if someone out there can give me their opinion i can show her friend that im not being unreasonable and get her to realize that i do need help and that its not wrong of me to need that. i will deal with everything else, i just need time to take care of myself. i know the job is hard, but doing it alone is at this point almost impossible and im scared if i dont make them realize this that they are going to let me go and find someone else and they are gonna treat her terrible i just know it, noone in their right mind is going to be ok with these conditions. despite it all i truly care about her and i think thats what frustrates me the most is that i do the most for her but treated like im a random employee when im really like family, help!