I have tried the sudo command, I have tried the init=bin/bash (or something like that - now I don't remember), I have tried the mount -o -n remount/ sw, and without the -o and everything that I have seen online. Anyways it doesn't work.
When I have tried in the root it doesn't show me letters, just figures of something similar to diamonds (idk) and I have notice that I can't write the letter 'm' there, I don't what is happening and of course I have no idea of how to solve it.
Also if nothings works I'am open to reboot ubuntu (18.04) but I have dual booting with Windows 7, if someone can tell how to do it the easiest way, please.
Thank you very much
Have a nice day