Angry, helpless and a lot of guilt

Caring for Father in my house for 5 weeks last month made me realized that  caring for an aging parent is the most difficult thing one could ever endure. He has lost a lot of weight. A once very healthy man who was very much into sports had now shriveled down to a mere weakling. He has now become incontinent and has to go to toilet every half hour, at most, every hour.  He refuses to wear diapers so I had no option but to give up almost all my sleep as his legs are so very weak that he has to be accompanied each time to the toilet.  

The most difficult part for me is not the sleep deprivation but the feeling of helplessness and frustration.  I feel angry that this is happening to someone so close to me, my Father. I feel helpless and a lot of guilt  for not being able to give him the best, not able to give him back the quality of life that he deserves.  I feel there just isn't anything I could do for him that would make him happier. He is making the motions, but his quality of life is no longer.

I remember physically caring for Mother too for about 2 weeks before her passing 13 years ago.  The memories came rushing back when I look at Father now.  Now that Father has gone back home as the domestic helper who looks after him had come back from her holidays, I am relieved of having to care for him.  But I cannot for one second stop feeling the despair and frustration.