When I try to boot my Mac in recovery mode by holding alt+R, the progress bar shows up as if it is loading the disk. However, when it finishes loading, it switches to a screen that has horizontal lines across it, which resemble white noise on a television. You can vaguely make out the Apple logo with small cross sections of it in the horizontal strips.
It eventually switches to another screen where you can make out the image of the recovery mode options, but, again, with the screen broken up into small horizontal strips with pieces of the image, but not lining up vertically. I can move the mouse around, so the computer isn't just completely frozen, but I can't interact with anything.
Is my recovery disk corrupted? How can I fix this issue?
My Mac is on macOS Sierra Version 10.12.6.