Is there a way to delete or manage all my labels?

By mistake someone at my work imported a list of users and created 1 label for each of them, that’s at least 5,000 new labels that were created by mistake.

I know I can delete the label manually, but doing it one by one will take me forever.

Is there any way to select all the labels I want to delete and make it easier?

Yep - Filter members by the label, hit the cogwheel, and then select remove label: