My google account signs in random users?

[Dwildkat]

I have been experiencing a strange problem with my google and youtube accounts. When I sign in either on google or youtube it displays another random users id and info on the homepage. Only after going to my channel or youtube inbox for instance does it display my data. Similar problem on google, sometimes it even changes my default language to chinese or arabic. Have I been hacked or something? My antivirus is up to date and I ran it several times already. I don't really know much about computers. Other accounts (facebook, twitter and Yahoo) are running fine. Please help.
Thanks

[Srinivas]

Its just a server problem of Google. Don't be tensed. It will be solved within a short time