TF2 downloading a 5GB update when it is up to date!

Hey guys,
I recently installed Team Fortress 2 through steam and it worked great and fine until one day i turned on steam to find that it had a 5 GB update! I've verified the local game cache about 6 times now yet it has done nothing and i've also tried defragmenting it. None have been successful. When i go into steamapps>"username">team fortress 2,
the size of the folder is 242mb yet my friend says his is 2.4 gb. I do not know why this is happening as it was working just a few weeks ago.

Any help would be appreciated!


EDIT: I pressed Play now my tf2 folder is 360mb and rising and it is still displaying the "Preparing to Launch Team fortress 2" window. This seems like a good sign

EDIT 2: Still Preparing to Launch. Folder is now at 526 MB. This is going to take a while...