Its possible other servers were using the same hoster, but I don't really know. I can't really help you much. Do you use any mods?
Yeah, I can't really help then, if you've already tried restarting your router and you don't have any mods that might interfere, I'm not really sure. What minecraft version number are you using?
Yet, lately, I've really been screwing around with all my file , I really hope I didn't Screw it up D: