[Help] Won’t let me connect to my own server

So I hired someone to help me with my server configurations because I don’t know much about it, and this person wasn’t helping me at all I was doing all the work he only set my server up to put it online. So I retrieved half of the money I sent him to let him know he was not providing the service he said he would. But instead of helping he changed something and now when I open my main the login box won’t appear and I get disconnected from the server. The guy left and took my money.