I did the reinstall everything advice. PS store is under maintenance. So tomorrow I will redownload everything. I started up Skyrim(without loading my save file, that would cause major screw ups, cuz of my DLC items)and I checked the game data size..2678. Is it like installing while I play?

You mean your main skyrim game data is 2.5GB?
That should be right if that's what your referring to.

I play it for the 360, and I think its 3GB for the 360. Not quite sure though...

But on the back it says 5 GB. It's really weird. It's the game installation. Is this the problem for my crazy lag in werewolf or vampire lord form? But this increases every time I play too. When I first installed the game last year, it was 4369 MB. And my game freezes a lot. So I did this but PSN store MAINTENANCE FUDGE!!,