Chlorine + hot water during a shower can turn into chloroform gas, which was used as a general anesthetic prior to newer medications for this being invented. Since Lyme can cause the body to become more sensitive to chemicals, this may be part of the reason for the "new experience" of dizziness during/just after a hot shower. There are shower head filters you can get that will remove the chlorine from the water before it sprays out of the shower head that may help.
Chronic Lyme Disease, Bartonella (clinical dx only), Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, chronic Lymphopenia, etc.; G-Tube; TPN via PICC (plan to start weaning off again soon).
Meds: IV Cipro, Heparin (to flush PICC line), Singulair, Claritin, Domperidone, Colloidal Silver (topically & nasally), probiotics, digestive enzymes, Milk Thistle, Magnesium, homeopathy.