Successful Aging: How can I help others without overcommitting my resources and energy?

Q. I am widowed, down-sized and fairly comfortable these days. More and more, I am seeing the needs of people around me who really could use my help. Old friends and new are in need of support, hot meals, trips to the doctor – one even needs a place to stay. How can I be sympathetic with all of these needs without going overboard? I feel very guilty if I don’t help, but I don’t feel that I have the strength or the resources to contribute. Your input would again be appreciated.