Are you 100% sure you have a ban?
Normally US bans only kick in once you've overstayed more than six months (3 year ban) or more than a year (10 year ban).
Anyway, if you can't enter the US, then you are pretty much out of luck for saving your PR status. You can try applying for a PR Travel Document with H&C considerations. This is almost guaranteed to be refused but no harm trying. Once it's refused, your PR status will be officially revoked. At that point, you'll then need to apply for PR from scratch through an economic immigration program like Express Entry. Success will depend on your profile (level of education, profession, etc.).