If you get a phone card from the post office, sometimes you get a deal where you can call Canada free after 6pm
UK time. That should help on the money front.
As for the adjusting. I've been here since November and I haven't fully adjusted. I am not sure I ever will. It doesn't help that I am flying BACK to Toronto for my third time since July in December.
In your case, just think of it as an adventure. Your time here has an end date, so you know you are not stuck somewhere you do not want to be. Just relax and have an awesome time. And avoid the tube in rush hour because that can turn you off of London quickly!