You can obtain a transcript or a paper copy of your 2017 tax return from the IRS. A transcript can be ordered online for free and it contains the amounts from the lines of each of the forms in your return. To order a transcript, use
this link: IRS Get
Transcript
Plus, below is more information on obtaining a copy of your tax return from the IRS:
And, below are steps to be brought to the section of TurboTax to enter your loss carry forward amount:
https://ttlc.intuit.com/replies/3301508