Hello, I'm a 28 year old woman seeking help with my mother who has early onset dementia. Any advice?

I've been taking care of my mother for the past 8 years. I'm an only child and my family won't help us or me. I had to leave college and the city to help her. My boyfriend and I have been living in the same town as my mother for about six years now after she had five bypasses done before a major heartattack. She would not quit smoking and was diagnosed with COPD. She ignored everything told to her and continued chain smoking, she started showing signs of dementia about four years ago...if I'm honest even when I was a teenager. I remember a year when I was 16 and couldn't understand why she couldn't keep food on the table a few times, our lights and heat were turned off in that year during the month of January and we live in Canada! I remember we kept warm by sitting beside each other in the dark with a blanket eating crackers and jam because that was all we had....in one of the richest countries in the world. I'm an only child and thought this was normal....I didn't realize how ill she was getting since I was still a kid. I remember fighting with people over the phone to keep our hydro on at the age of 16 and going over he bills because she just would give up and get angry and tell them they could fuck themselves. It was very odd behaviour and I never understood it until Two years ago in January, the same year and month covid hit that I found my mother laying on her apartment floor completely dehydrated and covered in a pool of her own urine and sweat. She had been stuck there for up to two days. I called the ambulance, they said she had a urinary infection because she had recently just become incontinent and peeing herself at work, she got let go because it was a health hazard as she was working in a grocery store. She wasn't taking care of herself or showering or changing her pee pads, so she got an infection and she fainted and had a stroke. If she had been found earlier perhaps she would have done better, but now she has brain damage and is quickly declining. She was diagnosed with early onset dementia. I've had to be with her almost every other day since. She can barely walk, we had to take the stove away, she won't eat anything else other than pizza pockets even though I've given her home cooked meals they just rot in her fridge. She says she doesn't like "left overs" and wants her stove back. She will only eat sweets and junk which I think is tied to her smoking habit. I had to take her cigerettes away becasue she would smoke up to 40 cigerettes a day if I didn't! We had five complaints from her building threatening to have her evicted because of it, so it got to the point we had to take her debit card away because she was spending recklessly and taking cab rides that would cost her up to $300/month on a $700 pension plan. It got so bad I was paying for her groceries, so I took her card away to manage her money better and now she says I'm stealing from her and she keeps stealing back her card when I visit and go to the washroom out of my purse and hiding it so that she can take off when I'm at work to go and get smokes. I have gotten two call so far from her psw saying she was caught wondering, and even random strangers have picked her up from the side of the road because they saw she was stuggling to walk. Walking fifteen feet can take up to 8 minutes for her at times because her mobility is severely constricted. She refuses to acknowlege her decline and refuses help and denies everyone and everything. She lies and ignores people whent they try to interact with her. It's to the point where I'm so confused and exhausted and have no idea what up or down is anymore. I'm only 28 and my entire youth has been spent focussing on my mother, and taking care of her so much that I haven't had a change to even plan or build my own future. She's broke, I'm broke, my boyfriend is broke. My boyfriend and I also work full time and currently I have two jobs and have taken care of her all through covid. I'm feeling so burnt. HELP!