Well, if you haven't been served then you don't have to go to court. But they might say that you have been served. Go to court and look at the file to see if they are claiming that you were served.
There's a lot of money here, you certainly should have a lawyer to help you here. I hope you've been looking for one.
Go to mysupportcalculator.ca and use their basic free version of the spousal support advisory guidelines, that will give you a range of supports. See where their proposal fits into the recommended range of amount and duration. Play with the numbers, both for 2015 and current incomes, and for her imputing incomes of various levels. And as you say, if she's living in your home and you're paying the bills, you certainly should get credit for that too. Don't just accept her lawyer's offer, obviously they are going high.
And the best advice is, get a lawyer, start gathering the information needed for your documents, think about what you want in an order, and instruct counsel appropriately.
Anything else to discuss?