Yes.. most of us do expect that PAD would only last for a short while after the movie's screening.. but it reaches far, far deeper than that.
Personally, Avatar has changed my outlook on life - I'm becoming more rational, more observant, more sensitive to my surroundings. While yes, I do agree that Avatar has left a gaping hole that is incredibly hard to substitute, I feel that I am able to analyse things in a more clear manner. And instead of becoming more depressed about being unable to be on Pandora and with Neytiri, I start pouring my efforts to improve myself, in the goal that someday I can and will be able to leave my mark (hopefully something positive).
Anyways HNM, you're definitely not alone here, many others here will share similar sentiments as you. Its good that you speak out your frustrations and sentiments here, so our community can relate with you and offer you a listening ear