I need help with my aging Mom.

My mom has I am not even sure how to describe her anymore. I am actually caring for her right now. When I was young she was always putting me off on someone or leaving me home alone with my father so she can do something. I am the youngest of 3 children I am actually the only girl. I have two brother's one passed away sadly. Now my mother who is almost 68 is showing signs of dementia. My granny her mom had this but my mom's seem to be different than my grandmothers. As of recently she has started keeping a calendar marked of every day a new toilet paper roll is put on the toilet paper holder. She throws her money situation in my face constantly saying I have this and that to go on. She dropped from paying for my lock up which honestly I never asked her to do in the first place. She is still able to work though she comes home to complain so and so done this. I honestly get tired of hearing it and if I say something about me not wanting to hear it any more she gets mad. I have had to ask my ex husband to help me get my groceries and etc now cause she is blaming me for being low on money in her checking account. I am not able to work due to not having a vehicle and no one around my town likes hiring anybody that doesn't have a vehicle. I have been turned down many times cause of this. As of recently I found a job online plus I also own my little craft/sewing business but she constantly telling me I need a real paycheck like she does. She is very belligerent I am always trying to ignore her. Though lately its not helping cause I thought it might then she would stay quiet. She has started to forget where she put this or that. Then she forgets that she told me something already I have to tell her. I can not talk to her nor explain something to her without her saying to me"ok ok ok shew or phew". When you try to hear something on tv that is important she is constantly talking right over it. If the tv is loud she always says out loud well the tv turn itself up again. As of lately she has been telling me something is biting her but I am not seeing anything flying around. I am the one doing mostly the cooking except for every other Sunday,I do lot of the cleaning around here the only thing she can clean is her clothes,her side of the sink,and every now then the kitchen. If I cook she whines she has to do the dishes though we have a dishwasher in the house. She won't even lay a finger on the vacuum cleaner what so ever and she likes to spend so much money on my great nephew. Then afterwards complains about money after buying him something. When someone ignores her while she is talking to them she gets pissed. She is always putting me down or making fun of me even I am right there in the room. I am not even sure what to do anymore. My brother is no help cause he and I do not talk. He has a problem with me but why I don't know. He takes care of her vehicle and her really to be honest with you yet she is more grateful to him than she is me. He and I are both are trying to care for her just seems like she is more thankful for him taking care of her than me. She got mad when she found out I had to move back in with her after my divorce. When I told her she was like no you are not moving back in here I have no room. It took my stepmom to convince her to let me move back in for a while. She has been throwing a lot of that in my face as of lately. I have been here a year and half just wish she was more thankful/grateful I am just in case she falls again or what not. She is also all up in my business especially my private dating life. I try to show respect to her by telling her I will be going out of town and you have my cell number if you need anything. But she is constantly asking me who are you going with and etc as if I am a teenager. I end up saying you have my cell you know where to call me if something happens. Help I don't know what to do anymore! I have a lot of depression and anxiety cause of her controlling/mental/verbal abuse since my father walked out on us in 1993.