My pup got his tail amputated?

So my puppy (5 months old, lab/poodle) got his tail caught in a door (bone was exposed and he was bleeding) and so i went to the vet and they bandaged it and told me to come in a few days later to check and so i did and they had to amputate 3 inches, He has pain killers and antibiotics. And so uaually he goes to sleep at night at 11 pm and wakes up at around 7 am, and even when his tail was bandaged (before amputation) he was still sleeping normally, but he sint having his regular naps in the day and well its 4 am and he still hasnt gone to sleep for the night. Even before amputation and when he was fixed he didnt whine at all, but now he is which is understandable because of the surgery but its just not that normal for him. He just keep looking at his tail and whining and looking at me and whining, just back and forth between me and his tail. Now im wondering if this is normal with other dogs that have had their tail amputated. Also he has become more agressive, now im sure some of this is because of his fusturation cause he isnt allowed to exercise but its even when he is calm and im just petting his head and then he will just randomly bite me (not playfully but angrily) he used to listen to "no" before whenever he would bite as a smaller puppy but now he doesnt really listen. I just wanna know how things were for other dog owners who have dealt with tail amputation.also is tail is completely bandaged and it has a hollow plastic tube thing over it and so the vet said it wont hurt when it touches things. Also he doesn't react at all when i reach for his tail and he lets me pick it up to check how the stitches are.

There are a lot of nerves in dog's tails. This is the main reason why cosmetic tail amputation is such a big debate. He is old enough to have these nerves developed. It is kind of like when a person looses a limb, that area is very sensitive for a while and the people say they can still "feel" the missing limb. It is going to take some time for the nerve endings to die, hopefully the pain killer helps. The tail hits things when he walks and touches things when he lays down so these nerve endings are always firing, which is why the vet told you to restrict activity. This could also be why he is acting more aggressively. He might fear you are going to reach for his tail and thus he reacts. Also he could be having a reaction to the pain medicine but that is rare. It is more likely that his attitude change is due to the pain in his tail. As the nerve endings die he will return to his happy self. Happy Healing!