I am not an expert in cannabinoid therapy. I am just a citizen scientist experimenting on myself... As are most medicinal cannabis patients. I am passing on information that I found useful to me. I am not endorsing any treatment for anyone else. You know your body. I don't.
We have very limited knowledge about CFS/ME and very limited knowledge about our endocannabinoid system - and very limited knowledge about how medicinal cannabis works with our endocannabinoid system. There are very few articles or research in regards to using cannabis to treat CFS/ME; i.e. we will need to think outside the box and find our own way with this medicine.
Do your own research and don't limit medicinal cannabis research to any single condition. Learn from others with similar conditions and similar level of disability who are using cannabis therapy effectively. My pathophysiology has similarities with MS. So I research the science and anecdotal evidence for treating MS with cannabis.
Learning how to make and use a non-psychoactive cannabinoid tincture is a good place to start. For those of us who are very sensitive to medication/environment, and little/no experience with cannabis, I suggest start with non-psychoactive forms of very low potency and then increase very slowly. You may not feel anything... I didn't. With THCa tincture your not supposed to feel anything. But it was working, slowly, gently making changes behind the scenes.
Briefly, THC is the main psychoactive component in cannabis. But the cannabis plant does not produce THC. The cannabis plant makes THC acid (THCa). THCa has medicinal properties and is non-psychoactive. Back in the day, the US formulary contained instructions for preparing THCa Tincture. That was what medical doctors were prescribing for many conditions at turn of last century, when cannabis medications were legal. Medicinally, THCa appears to have similar medicinal properties to CBD in many conditions.
Usually, cannabis is not psychoactive unless heated to temperature that decarboxilates THCa, turning it into THC. Decarboxilation can occur naturally but is a very slow process. Occurs by losing carboxyl group through aging, curing, and exposure to UV, etc.
Cannabis in it's natural living state is not psychoactive. Very humorous to medical cannabis community when DEA in Utah(?) claimed they were worried about wild rabbits getting high off of cannabis plants.