Daycare while having an infant of your own was the most difficult years I had while operating my daycare. All I can say is children will cry while they are adjusting to the new environment. If you put me with "strangers" and told me to go to sleep it would take me along time and I might even cry.... Don't give up on children too early, they are going to need time to adjust irregardless of the age. Your son will have many benefits of being with his mother will far out weigh a few days of a messed up naptime....it gets better. Also be careful not to stress the negative with new parents, focus on he positive and make suggestions of what they can do to help you in the areas where their child may be struggling. Keep going and try to be positive going forward....good luck.