Hey Lisa Marie - Wisco,
We understand you're experiencing display issues with your MacBook Air that are getting worse.
It sounds like there's likely an issue with the cable connecting your Mac's display to the logic board or an issue with the display itself. If you continue to have issues after booting up into macOS recovery, this would confirm a hardware issue. In order to boot into macOS recovery, hold Command + R after turning on your Mac and hold until you see an Apple logo.
If you've confirmed the issue is hardware related using the steps above, you can use the following link to determine the service options available in your area:
Get Support
We hope the above information helps get you on a path to resolution.
Take care!