i agree that there could be some other imbalance in the system so providing more of one thing - could just cause more of a log jam somewhere else and the mitochondria to produce more free radicals
but the other option worth considering is that you may be suffering a die off reaction from the anti-microbial effects of some of these supplements
methylene blue is actually a powerful antimicrobial - it was developed as an antimalaria - but Zhang et al at Johns Hopkins recently found it was particularly potent against bartonella bacteria in vitro - more so than any of the conventional antibiotics normally used to treat that infection - i mention this as i recently found bartonella is the cause of my CFS and PEM
there is a great deal of symptoms overlap - general blood tests etc are usually normal in both chronic Bartonellosis and CFS - diagnostic testing is v poor - and as a result i suspect there are many people with CFS who actually have bartonella or similar infectious disease.
methylene blue is also a powerful biofilm disrupter
NAC is antimicrobial for several common infections - and also a biofilm disrupter
many people in the chronic bacterial infection community that i speak to have reactions including increasing fatigue and often body aches etc from both NAC, and methylene blue
there are also theories which propose that CFS is driven by some biofilm forming colony in the body triggering adverse reactions - eg Markov's theory of CFS discussed on this forum
this is the best primer on bartonella - by two of the world leading researchers / clinicians
Ed Breitschwerdts has been studying it for over 30 years - all of his work is first class
Bob Mozeyani specialises in treating patients with Bartonellosis