I would say since your meds have been working to go the gp route. It's a pain, but if you can get the referral to your old psych, maybe you could then call the office directly and get in a bit sooner.

If you are in danger or in crisis, then the ER is the best route. They can set you up with a long term doctor after you leave inpatient.

I hope it works out positively for you. I don't know what the red tape is like in Canada, but here in my part of the US it can take a long time to get an appointment.

Good luck.