virginia

i live in the district of columbia and i just got fired from my job in alexandria, va. the reasons given were "poor performance and too many missed days of work." my health has been causing me to miss quite a few days of work, and i had spoken with management about it, made up hours, and provided documentation of my various doctor visits. this last friday i was told by my new doctor that i must take a week off to recover and she provided a note. i emailed this to my boss and on tuesday she left a voicemail saying i was fired.
what course of action might i take in this situation? i believe this is wrongful termination which presents an undue hardship and would like to request a significant severence. at the very least i would like to report my employers to...anyone who might be able to help me. labor board?
i don't know anything about unemployment. do i file in dc? how?
someone told me that my employer might be responsible for providing insurance for the next 180 days after my termination, or have to provide COBRA?
thanks for any help you might offer.