Mother being financially irresponsible and depending on my fiance and I. What can we do?

My fiance and I currently live with my mother-- I attend college + work from home and he works a full-time job (he is also interested in going back to college). We eventually want to move out and be on our own (I am 22 and he is 25 so we of course want to live our own lives). My mother is 64 years old and very irresponsible with money. My fiance pays her $150/month rent which pays the electric bill, we buy the groceries/food (she rarely has money to help), and we pay the cable bill + phone (two services that she wants but we ended up paying for it--- we also pay for internet but we need that and she uses the wifi anyway to play games + apply for loans and scroll Facebook). She needs the phone to talk to my sister (an irresponsible woman who bums off my mother) and her boyfriend (a man who practically uses my mother for rides and I believe for her money). My mother does not work and draws partial retirement off my father who passed away in 2012 (she quit working because she felt like it). We are stuck having to do house repairs, paying bills for her, and other stuff. She is constantly applying for loans that she can't afford to support her restaurant food addiction and irresponsible spending (she literally refuses to cook and won't let us-- unless I buy groceries and set my foot down). The only bill she pays is for her vehicle + car insurance + some of her debts. She is behind on lot rent where she lives + did not pay her property taxes. She gets a little over $1000 a month and should be able to budget it. We help where we can but we are honestly wore out and it is putting strain on our relationship. I do not know of a single person our age who has to deal with an irresponsible parent like this. She recently consolidated her debt (yay a good thing) but is putting herself back in debt. I have mentioned moving out eventually because we need our own life/privacy and to work on our relationship + build a life but she was moody about it and said that she can't afford to live on her own without us. She basically guilt trips and pouts while telling lies to everyone (that we don't help out and are freeloading when technically it is the other way around). What should we do?

Side note-- Besides the obvious financial issues she expects us to jump when she says so, to do what she wants 24/7, and she leaves little to no room for negotiations or our own lives.