Why is my phone screen is glitching

@resturestu "glitching" is not a good term to describe any failure of the display. It would help if you could use more descriptive terms ;-) You did mention that your phone fell, based on that I would suggest that you have a damaged screen. Time to replace it and to re-evaluate.

Since iFixit does not yet have a specific guide for that, use something like this video Replacement displays are readily available at many places.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same issues with their phone. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!