Yes i accepted now that the money is gone. I factory reseted my computer now and changed all my passwords. I wont use the wallet at blockchain info anymore. I already got elsewhere an other one and everything just worked fine after the factory reset. Thanks to all of you for your help.
That just confirms that you were infected by a virus and not some kind of bug on blockchain.info's end. I'm still using my personal blockchain.info wallet without any issues. Unfortunately, the hacker just got the better of you this time.
Next time, avoid this by always having an up to date OS, install all patches, have an antivirus. I personally use a mac so i don't need to worry about much since most viruses target windows, but i still carry out these procedures to safeguard my funds. Bitcoin is irreversible, so you should always put the safety of your funds first.