Starting Point machine [Vaccine]

I stuck at the last step… At the beginning it was successfully connected to reverse shell and I reached step with pg_hba.conf but while I’ve been messing with vim (didn’t really get it, do I have to write down :!/bin/bash to the file?) the session was terminated a few times, and now I can’t connect to shell, it’s always like this: https://i.gyazo.com/e017f850cb5acffcb437a4a03c94d50c.png and there’s nothing on nc