I do know exactly how you feel. I was in Korea for two years, then left to travel. Within those two years I returned to Canada, and ran into issues with my visa, and could not return as quickly as I would have liked. It was hard! I called my preschool students once a week to talk to them!
I left Korea after two years, and travelle. While travelling I didn't miss much, but when I returned to Canada, I realized how much I missed it. MIND YOU- back in Canada I was staying with my parents, with no apartment of my own, no job, no car, and even no cell phone - all things I had before moving to Korea in the first place. I found it tough. I missed my lifestyle in Korea. I did end up coming back, and have stayed another two years.
One thing I suggest - do not expect everything to be the same when you return. Minor frustrations will creep up faster than they did initially. I was nervous to come to a new city, but I so so glad that I did the second time around. It gave me enough 'newness' to appreciate things, but I still felt comfortable enough to do things on my own.
If you are in Toronto, then you are not far from Little Korea. Up at Highway 7 and Warden Avenue they are many Korean restuarants and shopping areas. Perhaps getting out there and picking up some comforts 'from home' will help!
Either way, best wishes!