Welcome! ;) Glad it's fixed!
Installing via Moodle Admin GUI does check for compatiblity of a plugin ... and if that fails site should prevent a 'train wreck'.
Moodle is backended by DB ... once one goes forward with updating the DB, to provide a 'cancel' or 'un-do' something in DB must retain former state of the DB (since there is now versioning in everything moodle). Coders haven't gotten to that point yet.
That's why it's best to research plugins first before attempting install *and* performing a minimal backup (code + DB) + knowing how to restore that minimal backup should something fail.
Well - you've gained from the experience ... and learned maybe what to do and what not to do! Growth! ;)