I keep getting disconnected

{URGENT} So here is the story, I put the random tic speed really high by mistake so now whenever I join the server it disconnects me before I can fix it this is happening with everybody joining please help we worked hard on the server and don't want to lose it. How can I fix it?

PLS HELP

Sometimes I get the message 'timed out' or the message 'disconnected' or sometimes the message "Connection Lost Internal Exception: Java.io.IOException: An existing connection was forcibly closed by the remote host

Now I realized that whenever anyone joins the server stops like 10 seconds later pls help!!!!

I am using Spigot 1.13.1

Help me wizard

and sorry for the late responses I have a different time zone!

I can't put any commands because I cannot join the server.

I tried that it still disconnects me

Another question when I upload a world why does it not generate

Whenever I upload a world to my new servers, when I enter the server I either get a random vanilla world or a flat world how can I fix this?

Yes I watched it many times and followed it correctly.