My Anxiety

I am new to this and don't know what I should be saying or doing.
My anxiety derives from being out of control of the situation. I have always maintained my own life, way of living, dealing with others, to the degree of being usually alone and ok with it. I try not to bother others and try not to be bothered by them. But now my life is in a cyclic hell with my having little time to be alone or do anything I like but instead I'm forced to be where I don't want to be where I have to do what I don't want to do and don't think is the right thing to do, either.
My elderly mother who recently has lost her sight (within the last few years) and already had a congestive heart failure and has a husband with continually worsening Alzheimer and has a daughter that is mentally handicapped (she is at a ten year old level of intelligence and maturity) got sick with pneumonia and almost died in the emergency ward. This progressive failure was added to by an overbearing son (my brother) who has all of his bills paid and is given $20 a day by my mother for the last 15-20 years. He has done some things for them over the last two to three years like grocery shopping and fixing dinner and checking on dad's catheter (spending about an hour or two a day) but at the same time arguing, bullying mother and sister. He also frightens my sister which only adds to the tension and stress my mother was having.
This drove her to want to place my father for care of his Alzheimer but for the brother who didn't want her to do this because he wants to inherit their money and not have it pay for my father because then they will not be able to continue to pay his bills.
I'm not perfect. I only visited them on Sunday spending about 4 hours and would take them to doctor appointments because they could not easily get into his blazer. Also being unemployed for the last two years I have had to also gain financial help form my parents. But after my brother getting it for 15+ years and I only getting it for the last year and I only getting $800 to his ~$1600 a month, I did not think it too much. But I know it did add a little more stress that wasn't needed.
It took me till only last July, 2011 to realize that I should not add tension and so I stopped arguing or causing any strife with my brother and sister as best I could when I visited.
Now my mother may be dieing soon, my father is getting worse and worse and my brother wants them to all be in the one house with him and me trading days staying there to watch over them. So half my life I am away from the peaceful home I have built for myself over the last 20 years of working and paying for myself, doing what I am untrained to do and unprepared for while my brother bullies all of us and won't take any measure to find the proper care for my parents. Caught in this half world with no control but to say I won't do it anymore and let my brother destroy my whole family I am having anxiety attacks, worsening health and fits of sadness that I have not had since my wife left me in 1991.
It took me a couple years but I got myself together after that but I remained friends with my ex wife and her new husband and was ok with my life living it alone and fairly happy most of the time. Now I am caught in this whirlpool of emotions, dealing with my father's illness, the possible soon death of my mother, the sadness of my mentally handicapped sister who I love and the overbearing anger, bullying and hostility of my brother.
I am doing my best to stay calm, find some peace, distract myself and maybe still have friends and some sanity but I don't know how long it will last.