Hi, rnihells, welcome to the old farts club. You sound pretty lean already, are you just looking to stay trim? Most folks on this forum are fighting to get as strong and/or muscular as possible. For example, I'm 55, 6 feet, 215 lbs and consider myself unbearably skinny.
First, what does you doctor say? Do you see a chiro or physical therapist? How's the diet? You say you have problems with DBs, do you use barbells or machines?
And how on earth did you manage to retire at 55?