Im angry

Ok so i have advertised my server on planet minecraft (Here) and it was going all good until 10 mins later some -guy- hacked the server promoted everyone now i had to stop the server ban him ip ban then somehow he re hacked me AGAIN! now i can only run a server with 5 people because im scared that someone will hackme again it really sucks now my server won't be popular!
i know alot of you guys are a honest bunch but sorry but i can't trust you