I moved to Edinburgh a month ago for a university-exchange and it took me several weeks to establish a routine. By now, though, I'm really starting to love the city, and I think that'll be even easier for you since you've visited already and since you'll be moving here once the days are longer and the weather is better!
Moving anywhere new, as everyone else said, does take a lot of courage. I've certainly had days when all I wanted to do was fly back to British Columbia and crawl into bed. But I'm sticking it out, and finding that my patience is being rewarded more and more frequently. There is SO much history here, and SO much culture, and being so close to the rest of
Europe really opens up the possibilities for travel.
I agree with the others; just don't stress yourself out by
trying to understand and process everything all at once. Let it come naturally, for as long as it takes to adjust. Jargon and local foods come easily enough; every visitor's guide to Scotland that I've seen has a glossary of common local terms. Make a list of things you're looking forward to here (and enjoying the company of your boyfriend full-time is a very valid example!); that'll help in the interim. It's really great that you and your boyfriend have discussed the fact that you're a bit anxious about the move. Keep relying on him for support where necessary.
If you're ever homesick once here, there are also other Canadians to be found (alongside people from all over the world, especially in the larger cities). A few international newsstands even have the Globe and Mail! Not to mention that the Internet and its familiarity are a real source of comfort sometimes. Just don't use it so much that you deny yourself the chance to get out and see everything over here!