How to stop common cold relapse?

You can't: There's not much you can do to avoid colds unless you want to live in a cave or on a mountain top, away from all other people. Getting a cold twice a year is just part of being human.

Prevention: Wash your hands often with soap and water for at least 20 seconds. Avoid touching mouth, nose or eyes with unclean hands. Cough into crock of elbow. Stay away from people who are ill.