Why do things not turn out as expected?

When Mike and I met we were far from spring chickens, we would often talk lightheartedly about looking after each other in “old age”. That time has come rather sooner than expected. Mike and I imagined that we would be caring with good humour and pleasantness, the reality is very different. Mike is miserable and bitter (I know it is hard to be infirm and ill) without so much as a thank you if I do something he has asked, and a far worse mood ensues if I do something he hasn’t asked.  All of this adds to my woes, how do I maintain the expected positivity and humour when all I receive is negativity and bad temper? I don’t know how others do it. I’m ready to run and keep on running. Poor Toni never gets walked, I never get fresh air (unless you count the air I get walking between the car and the supermarket.). My brain is fried, I can’t remember a thing, and my body is struggling to cope with the simplest tasks.  I can’t settle down and read, or even relax in the bath. Even as I sit here at the computer I can hear his constant cough……