DB Connection error after server upgradation GCP host

Hello all, today we upgraded our instance size hosted at Google Cloud. We upgraded from low RAM to high RAM, during this our IP address has been changed and from then we are facing Internal server error due to Mysql connection problem, and bench update returns error like

pymysql.err.OperationalError: (1045, u"Access denied for user ‘68d9751b6007dbe5’@‘ServerIPAddress’ (using password: YES)")

Can we solve this?

A good exercise would be to reset the root database password, that should resolve for you whether to use say localhost or ServerIPAddress to now connect.