Infighting

I had a bit of an off day yesterday and after having a chat with a friend about it had a few thoughts on the matter. I spent the day feeling rather negative, largely to do with some little things going on that I managed to turn into big things.
To be clearer, even though I know better I let some minor aches and sensations bother me to the extent that I wondered if there was something seriously wrong. It's a common complaint of someone who has suffered anxiety, and it bothers me greatly that I let my mind run away with me.
It seems to me that when there should be unity between the body and the mind they just keep fighting each other. When I was chatting to my friend about it he said, and quite appropriately, that if you want to find something wrong with yourself then if you look hard enough you will find something, regardless of how minor it is.
Life can be hard enough without being your own worst enemy, I reckon.
I'm also having difficulties with another friend of mine who just doesn't let other people in when times are tough. I really want to be supportive, and not just lip-service supportive, but he's good at not letting me, making him harder to care for than it should be.
The big issue is that there is a major event in his life and I don't know how badly it is affecting him because he won't show it. Occasionally I might get a glimpse, even tonight I could tell.
I'm doing my utmost to let him know I care (and he knows that without any doubt, I'm sure of that) and I hope that is enough, for now.