How to care for a needy parent?

I am the adopted only child of a very controlling, manipulative, and needy mother. She is a drama queen and master of the guilt trip.Throughout my life, her policy has been "children are to be seen, not heard". My job was to obey and keep quiet and out of the way. My adoptive father died when I was 9. She remarried within 6 months. That marriage lasted over 30 years. When he died, within a year she moved in with another man. That relationship lasted 8 years. His family said that towards the end, he was extremely unhappy with her and was either going to ask her to leave, or he was. But she still insists that was a perfect relationship. Now that she has no man, she has attached herself to me. This makes me really uncomfortable. I've tried to have a life, but every time she has a crisis, I have to move back to where she is, leave jobs and my dream location to take care of her. If I don't, I feel guilty, plus she has a friend who calls and tells me she is tired of dealing with her and I need to come back. She went off the deep end after the latest man in her life passed. So much so that I had to have her committed for a week. I don't think it was helpful because she's still nuts, even after going to daily outpatient therapy and having a psychiatrist plus medications that she would start taking then stop. When her man's family wanted her out so they could sell his property (and so they could have peace and quiet; they lived next door and she kept coming over when they got in from work), we moved her back to her house. My daughter and her kids were living there, but there was an attached apartment with a kitchen and bathroom that she wanted to go to so we moved her. Then she wanted my husband and I to move in too. Six months later, she had run off my daughter and her kids because of her intrusiveness, and I was angry and depressed all the time for the same reason. We entertained her every weekend, but couldn't go anywhere by ourselves without having to sneak out like teenagers. All she did was complain. She went to therapy groups and monthly luncheons with friends when we were at work, but that turned into complaints that everything was "boring". Then she decided to sell her house which was ok because my husband was tired of commuting to work. Next thing we know, she found an assisted living place that in her words was "heaven!". She wanted us to go see it and meet everyone so we did. Then we had to move her again. And when I say we move her- I mean we do all the packing, heavy lifting, and hauling ourselves. She is a hoarder and getting her to part with anything is impossible. Things she did agree to sell or leave, she did because her new place didn't have the room. Then she had us take stuff out and then bring either the same item, or something else, back again. I think she just likes issuing orders and watching everyone jump. She moved there last December and is already crying and complaining that "heaven" isn't a place she likes anymore. She doesn't like the food anymore, she doesn't like it when they have activities and the people from the dementia side come because they are "too loud" and take the staff's attention away from her. We moved last December too, to be closer to my husband's work, and yet every weekend we are expected to come get her and take her somewhere to be entertained. If we don't, we hear about all the other people who live out of state, who come every weekend or weekdays to see their family. I'm guessing these people are retired. We work. Now she's hinting around that she hopes we settle down (we live in an apartment) so she can come live with us. She complains constantly that assisted living is draining her bank account. She claims she cannot afford toothpaste or a cup of coffee, even though coffee is provided all day for free. Yet she continues to buy stupid stuff off the internet or from catalogs and eats out all the time when she pays for meals there! Her memory is getting really bad. Has been for awhile now, but her docs claim she's fine. I don't know what to do. If I have to live with her again, my marriage, my sanity, or both will explode. But I feel it's only a matter of time before either she comes right out and asks, since hints aren't working, or she starts performing a pity-party and the assisted living place calls me. I'm feeling depressed, angry, and resentful daily because I'm dealing with my own issues and yet she just doesn't care about anything I deal with- it's all about her. Sometimes I get brave and stand up for myself, then I feel guilty. Or when we visit or when I call, which is several times a week, she cries and complains and I feel guilty. I do understand why she's so unhappy, but she chose her current living arrangement. I agreed to it because she would have people around 27/4 because in her words "I just can't be alone". But now she hates it. I feel like I have no life of my own. Any advice from those of you who have "been there" would be greatly appreciated!