When your site was a 3.8.x (prior to upgrade attempt) did you make a site backup ... an archive of code, a database dump, and an archive of at least moodledata/filedir/?
Also, when site was a 3.8, did you view the environment check? Was that the screen you shared here ... the one that showed mariadb but a MySQL version number?
At this stage of confusion, it might be best to restore the 3.8.x site. Then double check the issue with your Moodle being able to recognize what DB service it's running ... mariaDB or MySQL .. and what verion.
If you made a site backup, but don't know how to restore, then we might be able to help. Your hosting provider help desk probably won't go there.
IF you didn't make a site backup, all hope is not lost ... but depends upon hosting provider. Many hosting providers do backup customer accounts ... ie, your entire server. They don't do that very often ... since this is end of June, their last customer site backup might have been first of the month ... 1st of June. They could, if they have that, restore it. That's means, of course, anything that was done on the site between the date of the customer backup and now is lost. But it's not all lost.
'SoS', Ken