So there is your issue. Your study permit was automatically invalid in December, 90 days after receiving confirmation of program completion. You are in Canada without status. Also, all work beyond receiving that confirmation was illegal.I will got my transcript in September last year. Must the transcript be sealed? If so I will have to pick another transcript on Monday. I got my diploma on 4th of November, I will got pick up my letter of graduation on Monday the 20th.
You need to apply for Restoration. You should NOT be going to the border, as CBSA doesn't take kindly to people who overstay and work illegally.