If you need your AGI from last year to e-file but are having trouble finding it, you can just print and mail your return (you don't need your AGI for that).
Yes. You can get a free tax return transcript or an exact copy of your return directly from the IRS.
If you need a copy for your lender, check which version you need. Most lenders will accept a transcript.
For more info about ordering tax returns from the IRS, see IRS Tax Topic 156.