Need the exact details of your problem, but you may also check for the following: (Be careful and keep the original backup handy):
In cPanel: Check the name of the database in phpMyAdmin of your newly created db and see if it matches exactly with that of the .sql file >> look for this line:
-- Database: `xxxx_yyyyyy`(xxxx_yyyyyy are just placeholders for the actual database name here.)
Also see if there is a proper user attached to the database. Note the user name, db name, and the user password
Using File Manager: In the wp-config.php file, insert those details carefully
This should help you log in if there are no other major issues.
The prefix attached to the original database name can be different than that being set for the databases on your hosting. So look at that first. Both database names (the original as well as the one you have created) should exactly match, or you should make necessary changes in the .sql file, and also in the wp-config.php file.
Else you'll have to go to cpanel and use phpMyAdmin and do more changes in the records (change path, etc,) within the wp-options at least.
try logging in now.
P.S.:
Any thing else, or you are unable to login still then will need to check further...