SQLSTATE[HY000] [1045] Access denied for user...

Sorry if there is a clear answer on this, I searched all over before posting this...

background info:

So today I wanted to work on learning how to send mail through my app, and have Sparkpost configured and ready to send things for me. I updated my .env file and only edited the MAIL lines. At one point in configuring my app to send a test mail, I had to do either

php artisan config:clear
php artisan config:cache
php artisan cache:clear

This plus a reset of xampp nearly had my test email go out, but I realized I didn't have a security certificate to actually send the mail. That's fine, I'll figure it out later (will learn how to test mail locally first).

current issue:

So now I just try to log back into my app and I get:

SQLSTATE[HY000] [1045] Access denied for user 'USERNAME'@'localhost' (using password: YES) (SQL: select * from `users` where `email` = EMAIL_ADDRESS limit 1)

Then I try to run any artisan command:

 PDOException::("SQLSTATE[HY000] [1045] Access denied for user 'USERNAME'@'localhost' (using password: YES)")
      C:\xampp\htdocs\Project\vendor\laravel\framework\src\Illuminate\Database\Connectors\Connector.php:68

  2   PDO::__construct("mysql:host=127.0.0.1;port=3306;dbname=DATABASE", "USERNAME", "PASSWORD", [])
      C:\xampp\htdocs\Project\vendor\laravel\framework\src\Illuminate\Database\Connectors\Connector.php:68

I have absolutely no idea what to do here. I didn't knowingly change any settings for the database/MySQL. All threads I could find with these errors simply say to run the config:clear command and restart the server and everything should be fine, but it's not in my case.

Any ideas? I'm completely at a loss. Anything at all would be sincerely appreciated.