I have been battling a flu for two weeks, despite providing a doctors note and informing them of my situation, I was terminated for missed days. When I informed them this morning that I have a headache and half my face was numb I was terminated and denied an opportunity for a doctor to verify my condition. Is that a lawful dismissal?

No - that is not lawful. You would not only be entitled to severance stemming from your termination, but you likely also have grounds for additional damages stemming from the employer terminating you as a result of your sickness, in contravention of the Ontario Human Rights Code. You should contact our office right away to speak with one of our employment lawyers so we can further assess your case.