Persistent horizontal lines and other issues on iMac M1 display

This issue began a month ago on my iMac M1 display. One morning, I noticed horizontal lines suddenly appearing. The right upper rim of the screen felt too hot to touch, and I also observed distortion and persistent ghost images. Today, the problematic area has now been immovable at the center of the flickering screen. However, I’m concerned that this issue might be escalating. A few days ago, other problems have emerged in various applications, such as Photos (when importing or editing, the interface turns pink), Preview (when opening images, the preview is blank), Pixelmator Pro (similar to Preview), and Safari (in some areas, text doesn’t display). Restarting the computer resolves these issues, but they only last for a short while. It’s been three years and four months since I have this machine.