There are different options available regarding tax relief, each dependant on your personal situation. The best way to avoid getting yourself into a difficult financial situation regarding tax, is to make sure that you always file your tax returns properly and on time. However, there are a number of circumstances that you can claim affected your ability to do this, in which case you might be given an extension.
The worst thing for you to do in a difficult financial situation, is to ignore it and hope that it goes away. If you do this, then it is likely to grow into a size that is utterly unmanageable, and then you may well find that your only option is to file for bankruptcy. Although this offers a legal opportunity for a fresh start, it is a drastic measure that you should avoid at all costs. You will find yourself facing a lot of barriers in the future regarding business and credit rating, and these will be difficult to overcome.
One of the easiest things to do, is to negotiate a payment plan with the Canada Revenue Agency (CRA). Now, bare in mind that their primary objective will be to obtain the money you owe them. If you can offer them a payment plan that shows they will get their money without having to take drastic measures, they are likely to accept it. This way, you can budget your costs and make sure that you have enough money each month rather than having to get your hands on a large sum all at once.
Another option may be a Consumer Proposal, which will allow you to pay off your debts over a set period of time and at a fraction of the cost you owe. There are exceptional circumstances required to be able to claim for this though, so the best thing for you to do is look into the details of all options available.