jetpack blocks login

Apparently, it wants me give it control over my site in order to give myself access.

I’m not sure I understand the issue. Could you let me know the exact message you get when trying to log in?

How do I uninstall this POS without access to my site?

You can follow the instructions here to learn how to deactivate plugins when you don’t have access to your dashboard:
https://codex.www.ads-software.com/FAQ_Troubleshooting#How_to_deactivate_all_plugins_when_not_able_to_access_the_administrative_menus.3F

Let me know how it goes.