The "return" you sent to IRS was returned back to you?  or the "refund" the IRS sent to you was returned back to them?

It's never to late. Correct the address and mail it again, and make sure you send it return receipt required.
Now if you owe taxes and you have already paid those taxes owed and your payment has cleared your bank, all you need to do is mail the tax return to the correct address, and you're done.
But if you owe taxes and have not paid your tax liability yet, then you will be assessed a late payment fee in the form of interest on the amount you owe. I would suggest you go to http://www.irs.gov/directpay and pay your taxes due immediately. Then print out two copies of your receipt. One is for your records, and the other is for you to include with your tax return when you mail it to the correct address. Then if any interest is due the IRS will bill you separately via mail for that interest.
Now if you do not owe taxes or if you have a refund coming, there will be no penalties or late fees assessed. But you still need to get your tax return filed with the IRS ASAP.  The sooner you get it filed, the sooner you get any refund if you are due a refund.
To get the correct mailing address for your tax return, see https://www.irs.gov/filing/where-to-file-paper-tax-returns-with-or-without-a-payment
Just click on your state and you will be provided with the address where you need to mail your **FEDERAL** tax return. If you need to mail a state tax return, then you need to visit your state's department of revenue website to find where to mail your state return to.

My federal return was sent to my address but was sent back to the post office because of what

@Montawilliams No one at TurboTax knows if or why the post office returned your refund check.    How do you know that happened?

 

Have you seen on the IRS site that a check was issued and mailed to you?