I normally stick to questions on 'travel', 'technology' and so on on here, 'cos I'm rubbish when it comes to human relationships but, for what it's worth, here's something from my own experience:
When my mum was dying (in the hospice ward of a hospital) I'd always try to be 'bright and breezy' when I visited her. For example, when I found that she was lying on a special bed, powered by air pumps, to help relieve her intense pain, I didn't commiserate with her. Instead I cracked jokes about her 'bouncy castle'. When I was about to leave the lady in the next bed (whom I'd never met before) asked if she could have a word with me. She said that my presence was "like a breath of fresh air" in the ward. She went on to say how much she hated seeing all of the doleful relatives visiting their loved ones, and that what the people in the ward really wanted at the end of their lives was a bit of cheerfulness about the place.
So, perhaps, (however hard it may be), you should seek to inject a bit of levity into the lives of your parents, rather than 'going all serious' on them?
OK, take it or leave it, that's my tiny contribution on the 'relationships' side of things (which I've already admitted that I'm rubbish at). On a more practical note, I've also found these herbal stress-relief tablets to be useful at various times in my life:
http://www.hollandand...odid=505&cid=38&sid=0
Chris