S.B.
I am looking forward to reading your answers, as I have a rowdy one of my own. My son is the same age, and when he gets the idea that he should be able to hold or play with something, or be able to get down and walk/run around, and you don't let him? Look out! He SCREAMS, cries, smacks us in the face, squirms and pushes us away, and head butts. Needless to say, he is no longer allowed to go to the store with us. We have not tried time outs, because I really don't think that it would be effective because I don't think he would understand. Also, I don't have a place to put him that isn't used for something else (sleeping, eating, etc.) and I don't want him to associate say, his high chair, with entrapment because I want him to want to sit there to eat. I like your pack and play idea, if I only had the extra room to do that.
Anyway, you are not alone. I strongly suspect that this is age related, and I really, really hope it does not last long. Good luck to you!!