The idea might fit: What happened to you might conceivably be explained by the re-emergence of your old CFS viruses, due to the measles infection. Let's say your CFS was originally caused by one or more enteroviruses, and/or one or more herpes viruses (these are the viruses typically associated with CFS). These CFS viruses you would have caught years ago. Let's assume that, by your program of rest and natural therapies, you managed to get on top of these CFS viruses, and they were more-or-less brought under control by your immune system. These viruses can never be eliminated from the body, but they can be tightly controlled by the immune system, so that you have minimal symptoms. Everything was fine, but then measles came along. Now measles virus is well-known to cause significant immune suppression in the infected person. So it is quite possible that this measles-induced weakening of your immune response then allowed all the old CFS viruses to regain the upper hand - and your CFS returned. Of course, nobody really knowns very much at all about the true causes of CFS, so this all just speculation.