I take nonstop damage

[CTShadow]

Hello,

im playing on the SF2.5 Server, one week ago I opened some chance cubes. In one of them there was a message, it was a math problem, something simple like whats 6 + 13, but i didnt wrote the answer in the chat, because i didnt care, after 30sec it said: "Wrong answer" and i started to see the damage animation, my hearts disapeared and i couldnt open stuff anymore, im now also unkillable, i tryed severalo ways like /suicide or let me kill by mobs or other players. I would like to continue to play on this server, because i love it, i got like 6days of playtime.

Yours sincerely CTShadow (my Minecraft-username)