I agree with @scylla, but have a couple of questions:
How did you obtain your PR originally?
If you are married, or a common-law partner to a Canadian citizen (by chance), have you resided with your spouse or partner for at least 2 years there?
I ask, because in some instances it could still allow you to meet the Residency Obligations to maintain PR status. However, I suspect you would have had to have been married or in a c-l relationship before you became a PR for that to apply.
Worse case scenario...apply for a PRTD under H&C grounds, but it may be a tough sell, even if you really do have H&C grounds.