Right, I would say not to worry. The test may be meaningful, and if so they will find a way to manage it just like they do with HIV.
Or it may turn out that this is not the right test for XMRV, or it may be a different pathogen (virus, bacteria, etc.) which is causing your disease (the pathogen might be the same
or different between patients). Of course, it could be the right test. We just don't know yet.
Before Singh's study came out, I was pretty sure of XMRV, but now I am not quite so sure. There will be more studies, and we will know more with time.
We do know some of the AIDS medicines work against XMRV, in test tubes anyway, so we know what ones to use in clinical trails if/when the time comes. There will doubtless be new ones also, designed for ME/CFS, if XMRV or another retrovirus is implicated in the disease.
ME/CFS is a serious disease, but it is hardly ever fast-progressing. Get as much symptomatic help as you can (pain, sleep) and test for and then treat treat for any pathologies you can (leaky gut, orthostatic intolerance or neurally mediated hypotension, tachycardia, various infections [some controversy exists over treating these], etc.).
So hang in there... and if you need something productive to do,
write your government officials and tell them how badly we need serious funding (and a new toolkit and disease page at CDC, based only on our actual disease with PEM, cognitive dysfunction, and low NK cell function... not mixed up with other fatiguing illnesses; they need help but separated into their own diseases).
We need to know about XMRV, one way or the other, and we need to study the other pathologies we know about, and find additional answers.