Sorry to hear it didn't work out :(
Curious why you feel that T-Bone needs to go to doggy daycare? For most adult GSDs, being left some place away from their owner with strangers and strange dogs isn't exactly "fun". I worked at a doggy daycare for about 9 nears and in that entire time there was no GSDs that came through that were IMO appropriate daycare dogs. Most really disliked being left by their owners, many would do nothing but check inside and outside all day waiting for their people. The ones who seemed to have a good time without fail ended up showing predatory or territorial aggression towards other dogs at some point. None of them were IMO better for having come to daycare. I took my own GSD to daycare with me very often but never, ever left her there when I wasn't working. She only enjoyed coming with me because she could follow me around all day, she would have been miserable being left without me.
GSDs are very people oriented and very bonded to their people. They are not intended to be dog park or doggy daycare type dogs. As a breed they are prone to same sex aggression and exposing them to a lot of group play may actually trigger that. IME it may also trigger on leash aggression and barrier aggression towards other dogs (not just in GSDs but in dog attending daycare in general). What would make T-Bone happiest, without a doubt is for you to spend more tome playing and interacting with him. Teach him a new trick a week, play fetch, teach him to find a hidden toy or teach him tracking, do weight pulling with him, take him swimming, etc.
While dog parks are a different from daycare, the behavioral issues mentioned in this article are IME also associated with daycares.
http://www.apdt.com/petowners/park/docs/DogParks_King.pdf