If you prepared your 2017 return in desktop software (CD/download) and don't have any of the 2017 PDFs or the tax data file, then the only other place to get the 2017 AGI would be an IRS transcript.
Have you searched your computer and backup media thoroughly for any PDFs or *.tax2017 data file? Also check the Recycle Bin. Or did you happen to use any cloud storage/backup service?
And if you have multiple Windows user accounts, log into each one to do the file search and check the Recycle Bin in each one.
You
may be able to immediately download a 2017 return transcript at the IRS
website at the link below if you qualify to open an IRS account there.
http://www.irs.gov/Individuals/Get-Transcript
If you are unable to efile, you will have to print, sign, date, and mail the return. To file on time, you need to get it postmarked before end of day April 15, depending on when your Post Office closes. Or you can request an extension. But with an extension, you still have to pay any taxes due by end of the day on April 15.
