From your comments, my understanding of the situation is as follows. Your late husband had a will at the time of his death and you are named the executrix in the will. You now have the responsibility of dealing with the estate including the payment of debts, the distribution of any assets to the beneficiaries named in the will and the filing of terminal personal tax returns both federally and provincially on behalf of your late husband. Because there is a restaurant with a mortgage registered against it, you are now facing a very complex situation.
I want you to IMMEDIATELY contact a lawyer who specializes in wills and estates, make an appointment with him/her and bring along all necessary legal documents including the will and the title to the restaurant with the mortgage and copies of any outstanding debts that were owing at the time of his death. You do not have the legal knowledge and exoerience to deal with this matter. If you try to deal with this on your own, you are going to get into serious trouble. Be sure to get the lawyer's name, address and telephone number. If a collection agency or any other creditor contacts you regarding outstanding debts owing by your late husband, tell them to contact your lawyer. This will allow you to devote your full attention to running the restaurant.
Good Luck and have a GREAT DAY