I would agree with the others, Tsukii. The "Game Master" does not appear to be legitimate in the slightest.
First, we do not receive or address tickets through the game interface. Nor do we speak with players through it. We have a specific tool available in which we take tickets, investigate possible policy violations and interact with players.
Second, though we are able to go in game when the need arises, we have a specific interface in which we operate though, which is not shown here. The only thing that looks remotely accurate is the outfit the character is wearing and the <GM> tag. Though given it is supposed to be from the GM's point of view, even that doesn't show everything it should.
Dot commands are usually the primary indicator that you are dealing with someone who is on a private server. We do not use such commands.
As for how they may have known specific personal information, Thunderwulf is likely correct in that you may have been compromised in some way.
Even if you were speaking with a Game Master, we wouldn't be able to tell you your browser history, or your age for that matter. I would highly recommend that you check your systems to make sure it is secure. Account and Computer Security