Can't stop server after installing DiscordSRV

Lately I installed the DiscordSRV plugin on my server (1.14.4 Spigot), I stopped it and tried to start it again, but it didn’t work. So I refreshed the website and it says it’s up, but it’s obviously not since no one can join. Then I thought I deleted DiscordSRV, but I actually deleted another plugin by a mistake and it still didn’t work. Then I got that plugin back and deleted DiscordSRV, and it still didn’t work. I can’t start it since it’s up and it doesn’t allow me, /save-all doesn’t seem to work too, and I don’t really want to kill it, we’ve made a lot of progress there. Could anyone help out?

I got myself to kill the server and it just switches between up and down every second.

It works now, but I’d still like an explanation for this if anything like this happens again.