There are many deficiencies and debilities where there is no cure and patients are taught to adopt themselves the steady loss of their abilities without falling prey to depression,accepting all without regrets.Old age is such a case where one has to learn this fact gradually. The more will-power is,the more patient will understand the fact and try to be less dependent  on others. Problem is bigger than said,person feel helplessness when he is not able to turn side for himself.
It is normal in life cycle but acceptance is another thing. Most find it inexplicable but sharing others can help a lot plus proper medication can help to gain physical ability. Try to shift focus-from illness and idle thoughts to spiritualism.Will power play important role in all mental, physical or emotional losses. Depression and irritation could be controlled by auto-suggestions like:-
What do you want and what are your needs? How you can change your circumstances? What are other alternatives? What are the chances of improvement and where and How? What is success rate?
What is the price and are you willing to pay? Your resources and chances of change without negative thoughts or presumptions,view all with selfless attitude considering all pros and cons.
When you have nothing to say,silence is better than uttering irrelevant.
At the time of adversity your positive points may turn into negative or viewed as negative ones again patience is best cure-one solution for all!