Canoes are known for tipping over, most come with enough flotation so they won't sink. Stock flotation is often just for neutral buoyancy, adding flotation is an option but if I have not done that, my canoe is likely to sink when I get in, and float back up when I get out.

Assuming, I can't get myself in the canoe and the water out (self recovery has failed). It is just me and my swamped canoe, no help in sight, what do I do?

I have not been drinking and I am wearing a life jacket (PFD).

Note I recognize that it is possible to get back in a canoe and bail out any remaining water, but it is also not always possible. Getting in without filling it with water, is a skill; lack of practice, environmental factors, or injury can make it impossible.