What options are there in Canada for treatment of severe depression and anxiety for pilots?
I'm not going to address the legal aspects of your question, but I will tackle the psychological side as I have a degree in it - although I'm not a practicing psychologist. It sounds like you have been through a bad period and are likely coming out of it into a better period, what you need to do is see a professional and get some help very soon. Everything seems impossible when you're suffering depression, but it's very treatable and you may still be able to fly.
It's in everyone's best interest, especially yours, to have you well and functioning. As you have stated yourself going without treatment is unsustainable whether you are flying or not, so there's two possible outcomes with treatment:

You're better and you can still fly: pilots can fly on anti-depressants in most jurisdictions, including Canada, provided they get medical clearance
You're better and you do something else

Either outcome you're better, which is miles ahead of where you are now. You lose nothing by getting treatment, things can only get better with it.
Drug treatments exist for most types of depression and bi-polar type disorders, and studies show that they are most effective when they are paired with counseling. I would suggest cognitive-behavioral therapy (CBT) as you will learn better coping strategies and thought patterns. Things will get better if you get help, so see your doctor right away.