You did the right thing by applying the instructions one by one
I don't understand if you have a problem with mysql or with tw login...
MySQL password? Did you check the password in db/local.php
login problem? I know that the procedure to save the password in the database changed between version (the md5 for the has value has not hte same default between release). If you try to change the password (the receipe is on this site in the admin faqs), does it help