Didn't you make a back-up?
As per the ToS, sites are deleted 10 days after they become inactive = after approx 24 days of not logging in to the forums. This stops the servers from becoming overloaded with unwanted accounts.
You could try opening a Support ticket & asking nicely if they have a back-up somewhere. But it's not really fair on staff to have to do this (if they even can do it) because there are thousands of members. If everyone requested this, support would grind to a halt!