My computer crashed and my federal taxes got deleted,How can I go back and file state tax for 2017

Yikes....did you use desktop software to prepare your federal return?  If you used desktop software the tax file was only stored on your own hard drive; it is not stored online with TurboTax.  When you prepare a return using TurboTax the information flows from your federal return to the state return. You cannot use TT to prepare a "stand alone" state return.  Why did you not prepare/file the state when you prepared the federal?  

Your computer crashed--for real-- and you cannot recover the federal tax file at all?  Do you have a printed copy of it?  If so, you could use that to prepare a state return on paper and mail it in.  In order to prepare a state return by hand you need a copy of the federal return in front of you for reference.

You might have to download/install the 2017 software again and re-create your federal return and state return.  But before you try that,  look all over your hard drive for that federal tax file--it might still be there. 

https://ttlc.intuit.com/questions/1901659-find-your-tax-data-file-in-mac

https://ttlc.intuit.com/questions/1900721-find-your-tax-data-file-tax-file-in-windows

To call TurboTax customer support

https://ttlc.intuit.com/questions/1899263-what-is-the-turbotax-phone-number

They are available from 5 a.m. to 5 p.m. Pacific timeMonday - Friday