Maree, I do the exact same thing. I seem to have a "come here for help" sticker permanently stuck to my forehead!! I think for some people it just comes naturally (the world needs ALL types of people) to help others and empathise but I, too, sometimes wish I could say no.
I guess, just as we pick our battles, we should pick our causes. If a person is in genuine need then thats fine, absolutley fine. If they are just attention seeking or draining our energy then maybe you need to step back and let them get professional advice and stop bugging you...
Meg tries to take her own advice and fails miserably..!! lol