Eating clean on a budget

So I’ve been trying super hard to eat clean and lose weight, it goes very cell when we have the right foods in the house but this past little while money has been tight so we haven’t gotten groceries in some time. We have food but not necessarily the healthiest choices. So I’m struggling to find something healthy to eat. Any tips on eating clean in a budget? I live in Canada do I’m not sure how the prices of food differ from the US