Screen flickers+ vertical lines; driver update fixed only temporarily

Several steps to this weird issue:

1. Shifting vertical lines appeared intermittently for a few days
2. Screen then conked out to where image would appear only for a second when tilting the screen, as seen in this GIF I made on imgflip.com
3. Plugged in an external monitor, but the HDMI outlet on my ASUS was super finicky and hard to get the image to transfer to the monitor. A light bump would cause me to lose the secondary image (primary image was always garbage)
4. Updated graphics driver, everything worked perfectly for a few days, after which the screen resumed its antics. However, the HDMI connection issue seems to be resolved

Ideas on what's wrong and how to fix? TIA!