You might try filling out the paperwork for the Family & Medical Leave Act and see if your days off/tardiness can count towards your time off under FMLA... See http://www.dol.gov/whd/fmla/index.htm
Also, you might look up the Americans with Disabilities Act - http://www.ada.gov Your employer has an obligation to reasonably accommodate you because your illness is an "invisible disability." I don't know if there is some way to contact someone associated with the ADA who can help you with this issue or not...
I hope this helps - take care,
Chronic Lyme & Bartonella, Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut issues (dysmotility, non-specific inflammation), UCTD ("Secondary Lupus-Like Syndrome"), Osteoporosis, etc.; G-Tube; TPN via PICC (trying again to wean off the TPN).
Meds: IV Cipro, Heparin (to flush PICC line), Singulair, Claritin, Domperidone, Colloidal Silver, probiotics, digestive enzymes, Milk Thistle & other liver support herbs, Magnesium, Progessence+ (wild yam + essential oils), Moducare, homeopathy.