Yesterday my friend started the server and today I am getting a crash sign.

Here's the problems:

DiscordSRV doesn't detect the {username} placeholder so try to fix that

And the big error means that the server is lagging and it can't really load the chunks in.

DiscordSRV is causing the huge errors. (it's trying to connect to the discord server or update the chat but can't)

And since there were so many errors, it couldn't handle it so it force stopped the server.

Here's the thing you should do to fix the problem:
remove discordsrv and try fantasticallysimplediscordbot