Having worked with people who have through illness suddenly lost there senses ie speech mainly...we looked to use the other sense to communicate.
I wonder if with time Murray stress with lessen as he adapts. With cockers it is there sense of smell which is major hence there use as drug dogs so maybe involving more use of his senses may help. Maybe getting him to sniff you hand more often then a gentle pat on the head, or a small treat in your hand or lowering your hand to his nose more as you walk him or around the house.
My boy is 15 next month and his sight is not good and he is partially deaf and certainly not as agile, but you would be amazed how his sense of smell is -plus his timing too, if the oven door open when cooking the sleeping dog is up and sniffing, he never misses a trick.
I do hope Murray stress lessens and I hope you find some way to reassure your boy.