I am sorry to hear of your loss of semps, Marilyn. I've been enamored of semps since the mid 90's and I would cry up a storm if I lost all mine. I think Lynn's approach to try other less sun-needy plants would be a good one. I have found other plants that have the rosette shape of semps so they might be an alternative to look into? Would be interesting to find out if they need as much sun as semps do? Some might not...
This is a Draba:
These are Orostachys:
This is supposed to be a sedum: