Yes, you must retake Org2.
If you take Org2 this summer (which most likely means July-August), ensure your home university acknowledges the credit as applicable to the course you just received a D. It would be a shame to take Org2 at a CC, but you couldn't transfer the credit/grade towards your college coursework. I've seen many students take Org at a CC only to find out their university academic affairs office would NOT accept the credit... and the students couldn't get a degree.
You could see if you could take Org2 online with UNE or a similar well-known, accredited university. Same concern applies when it comes to acknowledging the credit towards your degree.