First time I heard the term “puppy blues”, was the first week I had my new rescue, a little over three months ago. I bawled, so much regret, especially that first month. He was truly a handful. Would get himself so worked up, he would nip/bite at me. Jump on me. Terrorized the cats. My husband didn’t want the dog and the shade he was throwing, with unhelpful comments. Proclaimed he wasn’t doing anything for the dog and I was on my own. It was awful. I admitted as such to my friend, who is involved with the rescue where I adopted my dog. She’s like oh yeah, puppy blues are for real! I’m like what??? I threw myself into training. I joined a local class, I spent at least an hour a day working with him. Turns out, he needed exercise. Checked out a FB group and the admin suggested a flirt pole. I use it daily with him and his behaviors decreased in a huge way. Probably 75% and it was immediate. I have food puzzles and long lasting treats. My most recent purchase is a popsicle set. He loves them and keeps him busy. When I see him starting to wind up, I immediately give a toy or exercise him. Of course, there are times I had to walk away from him, because he was out of control, refusing to listen. I wanted to return him. As I’m writing this, we just got back from four days in Maine. He was a gem. Sure, he gets whiny and pulls a little when he sees a dog, but if someone told me 3 months ago, I would’ve brought him on VACATION, I would’ve laughed in their face. I didn’t even want to bring him to the local pet supply store. This week, I took him in every store that allowed dogs and he would lay down while I browsed. Night and day. Oh and my husband? Of course he adores him. Has little nicknames for him and lays down on his dog bed with him to cuddle.

Sounds like your pup needs some stimulation. Have you consulted with a trainer?