Luckily if you are using Ubuntu they made it incredibly easy to reset your password.
Then choose “Drop to root shell prompt” from this menu.
This should give you a root shell prompt.
At this point the system should boot up very quickly to a command prompt.
You could always hardware reset instead, but ensure to use the sync command first.
And now you should be able to login without any issues.
Linux Commands
Files
tarpvcattacchmodgrepdiffsedarmanpushdpopdfscktestdiskseqfdpandoccd$PATHawkjoinjqfolduniqjournalctltailstatlsfstabecholesschgrpchownrevlookstringstyperenamezipunzipmountumountinstallfdiskmkfsrmrmdirrsyncdfgpgvinanomkdirdulnpatchconvertrcloneshredsrmscpgzipchattrcutfindumaskwctr
Processes
aliasscreentopnicereniceprogressstracesystemdtmuxchshhistoryatbatchfreewhichdmesgchfnusermodpschrootxargsttypinkylsofvmstattimeoutwallyeskillsleepsudosutimegroupaddusermodgroupslshwshutdownreboothaltpoweroffpasswdlscpucrontabdatebgfgpidofnohuppmap
Networking
netstatpingtracerouteipsswhoisfail2banbmondigfingernmapftpcurlwgetwhowhoamiwiptablesssh-keygenufwarpingfirewalld