While olfactory receptors (responsible for smell) can be permanently damaged, they usually can repair themselves. It may take some time. The cold itself could have caused some damage. However, since this was after just one use I would stop using it all together and talk to your doctor.
Yes, it should reverse with time. The damage is rarely ever permanent unless the use of decongestants is abused. This happens to me as well. My sense of smell returns after a week or two of better health. I still use nasal sprays occasionally.