Team Fortress 2 constantly updating

So i updated team fortress 2 last night, and when i tried playing today it wanted another update but the update was 4gb, this also has been happening to my friend for the past couple of weeks where he had to update around 2 gigs every week, while i would update around 150mb on the same day. I tried restarting steam and my computer  but it still wants the 4gb update.

Have you done the obligatory 'verify integrity of game cache' thing? I can't believe the number of times I thought a games install was broken and this thing ended up fixing it.

I tried that and when i launch tf2 it'll say "preparing to launch tf2" and i let it sit for an hour and it still says that it is preparing, then i'll restart steam and when steam launches it says that there is a 2gb update

Okay nvm, one of my friends gave me a copy of their tf2 files and that helped.