5 Month Old Blues

MSP book hit it on the head. My cute puppy has turned into a nightmare. he has become very demanding, doesn't listen to all my commands, with the exception of his getting a treat. :roll: Since he is mostly housetrained, I have moved him to a playpen when I have to go out and after playing with him in the am; he also goes in their because he will continuously jump on me to play more. Then the whimpering starts. All his toys are there and chewies. I even fill the kong with cheese whiz and that keeps him busy for about a half hour, but after that, wants to be out and with my constant attention. I have ignored it and eventually it stops. he won't let me groom him even though I have been prepping him slowly for it and rather play with the tools brush and scissors. He doesn't like his head pet, never has, only on occasion. He has gotten much more hyper. Can't seem to stop him from jumping on me for attention.
I am not enjoying this phase of puppydom and I am not a needy dog person.
Is this normal for little dogs or all dogs? I have tried all the training exercises and he does sit, lay down, come- when he feels like it--got to spot, get in crate, - he knows all these things, just doesn't want to do them and has even ran away and tried to hide since he doesn't want to be restricted. He is a clever dog.
The good news is he is highly social and very good with strangers and little people. He also loves the bark park and will play with any dog, even 10X his size, if given the chance.