I'm already tracking the income and paying the income taxes on it via QuickBooks.
since I've already reported the income or do I still need to report the form?
You have not reported that income with the IRS. That needs to be done on the tax return you are filing. You probably have made "estimated tax" payments through Quickbooks.
So that income needs to be reported on your tax return for your business. As a separate thing, you should enter on your tax return that you made those Estimated Tax payments.