My Wife has Fibromyalgia, and some mental issues so I'm considering divorce read below before answering?

When we got married, things were okay, she wasn't really sick. She took better care of herself even though I still had to do the lion share of the work around the house.... I worked 3 jobs, took care of her our house (inside/out) and our pets. In the last year I've realized she is taking advantage of my good nature and am considering leaving. In the last 2 years she has gotten worse and only wants to take her medication and not follow any other recommendations by the doctors. She will not exercise, take her meds with water (as stated in the prescription) she wants to do what she wants and if I say anything she gets upset. She hasn't worked in about 2 and a half years and she helps her aunt about 5 hours a day and that is all she does. She does nothing and will do nothing to help herself. I've tried being nice and doing everything for her and then started trying to get her interested in taking care of herself to no avail. I'm now just getting mad, depressed and lost. I have no idea what else to do. I used to love her but I can't sit around and watch her destroy herself and I'm tired of the constant pitty parties. No matter what is wrong with me I have no choice but to remain quiet, suck it up and move on because if I try to talk to her maneuvers the conversation to her problems and that is it. She says she loves me and tells me she appreciates me but I think that is mostly just to keep me around. Why would you expect everything and give nothing to someone you love. I've never asked anything from her and at the beginning of our marriage I was happy to do as much as I could but I can't do it anymore. I've talked to her family looking for help and istance and I get nothing. They either laugh things off or just say "you know how she is, I just don't know what to do with her"... They don't try to make her understand what she is doing to her life or mine for that matter... Can someone please offer some insight if they have any... I'm very distraught at this point. I've been faithful to my wife even thought it has been over six months since we've been "together"... I have needs but once she takes her meds she is out of it. And a lot of times I think she is over doing it and not being truthful with her doctors, but I can't watch her 24 hrs a day to make sure she is doing what she is supposed to...