Hi tobee, so Tony lives alone now? How long has he been on his own if he does?
When I separated Jam from The Cloud he struggled for a while. It was odd as I'd have thought not being attacked daily and nearly killed anymore might have been much better! I think it can be that having never been alone since birth they can take time to adjust and feel lonely and vulnerable. He was absolutely fine after a while though.
Dasher was recently on his own for a couple of weeks while Whizzbit is mating and Dasher was waiting for his mate. The change in his behavior and personality was remarkable. I have no doubt he would have settled again, but it was interesting and quite sad to watch.
Is Tony in a space there are lots of places for him to feel safe in? Not too big, lots of little hiding places? Does he have a nice place to tuck away for is nest so he feels completely secure?
Give him time, I'm sure he will settle down again