EMF sensitivity appears to be a real phenomenon, although the actual mechanism for it is still being studied. Wireless radiation these days--including that from cell phones, cordless phones, wifi, baby monitors, and any number of wireless games, gizmos and appliances--is made up of radiofrequency/microwave radiation (RF/MW) and extremely low frequencies (ELF), and they are pulsed or modulated, which may add another layer of reactivity. Based on what I know and what I have heard from researchers, special stones, magnets, crystals, stick-ons and etc., don't make a bit of difference in actually mitigating the radiation exposure, and may in some situations worsen it.
From 1990 to April 2022, the list of studies on ELF and RF/MW effects on neurology numbers 702. Of that number, 574 studies showed neurological effects. That breaks down to 91% of the ELF studies, and 74% of the RF studies. So it's not crazy to think some symptoms may be related to exposure.
A number of people have noticed they get headaches, pains, irritations, even nosebleeds when using or exposed to wireless or other EMF, while others report difficulty with memory, mental clarity, focus or maintaining energy (more vague and general, but when you start to see a pattern emerging, you begin to pay attention to it).
As for reliable sources, here's where I would go: Environmental Health Trust (ehtrust.org), Electromagnetic Radiation Safety (saferemr.com), Environmental Working Group (ewg.org). These are kept up to date. You can also go to the Facebook page: Safer Cellphone and Wifi Project @safercellphoneproject