Is it permissible for me to take out an interest-bearing loan to purchase a business in Canada, knowing that I cannot find work and rely on government assistance, which is insufficient to meet my family's needs, and this is to ward off hardship and earn a livelihood?

The extent of necessity that permits usury is the fear of harm befalling oneself, a limb, one's honor, mind, or property. In such cases, it is permissible to commit a forbidden act to avert harm. However, in your situation, there is no necessity that permits you to engage in usurious transactions with the bank. And whoever gives up something for the sake of Allah, Allah will compensate him with something better. Usury erodes blessings and brings worries. Fear Allah and strive for lawful provision, and your Lord will not abandon you.