I have heard (I think it was Ben Garside on youtube in one of his several vidoes) that cannabis might affect the system for feeling fine again after the being had severe trouble. This would be said be a good guess, he mentioned. I think that makes sense: feeling relaxed and confident and happy "everything is ok", getting hunger because the being might rebuild its body.
Before I got uncomfortable ill I was still affected a bit (sub-clinical). Here THC could be a nice help, but I did it only about every two years for say two weeks. After I got uncomfortable ill there was no effect anymore. So I would think that a contribution of THC itself to CFS would not be a part.
It might though be thinkable that a sudden stop may have contributed? So presynaptical calclium channels would have gotten suddenly higher, and postsynaptical calcium channels would have gotton suddenly downregulated - what ever that might mean.
But now they are probably normal enough again and I think you would not reverse cfs by smoking again.
I think only this sudden event might have contributed as a part. And it should well be (if so) only a part because otherwise cfs would occure regularly when one suddenly stops smoking weed.
In my own theory this could have contributed to a disruption of synaptical roads in the basal ganglia (this is it, I personally think, and roads in the thalamus). In my case this seems to be exactly the case: In these structures there are metals which are found in chocolate. So eating small amounts of chocolate (not more than 9-36g) helps me, and additional zinc and selenium intake. Under this prerequisite I take vitB1 and vitB2 which would help the mitochindria (NAD and FAD respectively) in the "broken roads". Here I take one or two hours earlier the combo of taurine and gaba (only 250g each) as a guidance, reestablishing the back-foreward-direction (I think this is what has broken down, in favour of the geometrical "short sides"). I think tyrosine could also do. Will see if I will need vitB7, until now it doesn´t look like that! For helping beta-oxidation I take methionine after a protein meal and drink over the day the a lysine water solution putting some cyanocobalamine in as well (this might induce something as well, don´t know what). Both will help building up carnetine.
I just got to have figured that out. I don´t know if this is what - probably in variations - happens in generel, but if, I think it would not be detectable by any research method of today (maybe PET?).
PS: I also would have stopped suddenly.