What should I do to fix the topscreen?

A few years ago, after leaving my 2DS New in the sun for about five minutes, it stopped turning on. Today after much restarting, that little blue light lit up and the touchscreen worked normally, with some flickering. However, the topscreen is partially dead and is unusable. Also, there is a point on the top screen casing that seems to heat up much faster than other components:

I was thinking about replacing the top LED screen but was unsure because the touchscreen is flickering too, and because I’m worried that leaving it in the sun might have caused other damage.

What do you think?