If by deficit you mean your expenses are greater than your income (or your liabilities are growing faster than your assets), I would say your business is loss-making, unprofitable, or profitless (among adjectives).
If it continues to lose money, it will be ultimately be unsuccessful, because the success of a business is measured by its profits.
I do not believe deficit, at least in the financial sense, has a common adjective form. In speaking of government spending deficits, for example, we usually hear compounds such as deficit-related or deficit-oriented.