RuthHoney,
I saw something, maybe here, maybe somewhere like it, talking about going to a meeting and sharing and they were saying, sometimes you have to soften up and sometimes you have to harden up. I think for me one of my main agonies has been being too soft and worrying too much about things, like you said, that are not my responsibilities -- stuff that is out of my control.
I would say, in your case, you could stand to harden up. If we are too soft for too many people for too many reasons, it starts eating us alive and then we ignore our own well-being, ironically, over someone else's well-being. Lose sleep, blood pressure, tension, anxiety, depression -- all of that.
You don't have to freak out to show you care. Let go and let God, if you are of that persuasion, but the principle remains true.
How often does it go back to the serenity prayer? Controlling what you can, accepting what you can't and knowing the difference.
I also have a buddy that I worry about -- some. And what is his problem? He agonizes about so many things -- caring about people who things are just not right for, or for who things just might not be right for if one thing or another happens. My point is, the danger doesn't even have to be real. It can even just be imagined. I have to be careful not to worry too much about his worrying too much.
Please, grant yourself some peace.