My suggestion:

1.Most people think their speciality is narrow.It difficult to find a job with their background.This is a common error.
2.You are right.The job market in Canada is far smaller than that in US.
3.Before getting the Canadian citizenship,you can try to find a reserch assistant job in a university.
4. when you have received the notice/letter of becoming Canadian citizen,begin to find job in U.S.
5.You are still at the best age of your life. Don't give up.
6.Put the first choice on your current background.
7. Try to take part in a Canadian job search work shop made by native Canadian.Do not think this is useless.
8.You will win. I believe it.