It isn’t so much that he’s lost his werewolfiness (as Stiles calls it), it’s just that it’s … taken another form. So now Derek is human and has to deal with an actual wolf, and well, it’s not difficult so much as the fact that his wolf is as grumpy as he was when he was a werewolf, and Derek finds himself being growled at more often than not by his own damn wolf. Derek thinks he understands the reasons, and it sucks to see his wolf self outside of his own self, but until Deaton figures out a way to reverse it, Derek and his wolf are just going to figure out how to get along.
Everyone’s had their own suggestions for trying to settle the wolf down, but they haven’t worked (Derek can’t name it, not when it’s still so much a part of him - it would be too weird - though he was tempted to call it something for chewing on his leather couch last night and it sure as heck wasn’t his name).
Scott’s suggestion of trying to teach it in an obedience school didn’t work (he’s not allowed to attend puppy school ever again);
Lydia’s idea to growl and show dominance didn’t work by a long shot (in fact, he’s pretty sure that’s why he’s now missing his favourite pair of runners);
Deaton’s idea to subdue the wolf with a shot was responded to with growls from both Derek and his wolf;
Malia said something about wrestling that Derek might have listened to had he had any of his werewolf strength left, because it had been ages since he’d wrestled and had fun like that;
Kira was the one that suggested going jogging, and the wolf seemed to like that idea, but it still didn’t stop the growling and judgemental looks he gave Derek any other time they were together.
In fact, Stiles was the only one that hadn’t suggested an idea, which Derek found odd in hindsight because Stiles never missed the opportunity to say something scathing/witty/sarcastic, and this was a big of an opportunity as he was going to get.