[How to Download world but in console (no in game)]

need help downloading my world from the console because something blew up in my world after using a command

and i now cant get into the server. it kicks me out after a minute of intense lagging and gives me the error :

connection lost

could not connect to a default or fall back server, please try again later:

io.netty.channel.AbstractChannel$AnnotatedConnectException

i hope you guys can help