"I'm currently living in the province of Ontario. "
Under the Access to Cannabis for Medical Purposes Regulations (ACMPR) you will have to provide medical documentation confirming your diagnosis by a health practitioner to be able to legally purchase marijuana from one of Canada's licensed producers (LP); any serious medical condition will qualify you. The health practitioner can either be a physician with a valid medical license from the province/territory they work in; or a nurse practitioner. Once you have this document, you can register with a licensed producer of your choice in any province, even if it's not the province you reside in, as this is a federal program. LPs ship your cannabis through the mail only.