Guys, I think I know what its wrong. In coinbase I clicked on "0 confirmations" and then on "blocks", and it took me to this url:
https://www.coinbase.com/network/blocks

So the last block was "about 2 hours ago". I think this is the problem.

Also, why exchange? I thought its just a wallet you can use without any downloads. 2 weeks ago I already use it once for a much smaller amount, and everything went fine.

Thank you guys - I am new to this bitcoin thing.

Edit:
I wrote the support. Looks like a bug on the page. Maybe they dont know about this yet.