Have you tried Pattypan (https://commons.wikimedia.org/wiki/Commons:Pattypan)? That is perfect for bulk uploads. It also allows organizing metadata in a spreadsheet. The link above also has guides for using it for the first time.
I have created 476 files of animated GIFs of Kannada gunithaksharas. These are extensions of the animations found in this page - https://kn.wikipedia.org/s/ap. How do I do this other than manually uploading them?