Green vertical box in my macbook pro screen

If the display module is failing, which it appears it is, there is nothing you can do other than scheduling an appointment at your Apple Store Genius Bar for service options. It will likely continue to get worse over time.

Make sure you are backing up your MacBook Pro. The worst time to ask how to preserve data is after something goes wrong.

Thanks, that is a MUCH better picture. That looks like a vertical, Full height artifact.

The news is not good. The only way to have a defect like that is by a defective Display module. Cables and adapters and such can generally not that sort of defect.

Such matters are dealt with ONLY in person at your appointment at the Genius Bar, or at a service depot or Apple authorized service provider if you choose to send it in.

To my eye, it appears to be glass breakage, with a visible impact. Apple will have to see it and give you your options. Threatening other users you won't buy another MacBook again doesn't help you or honestly make much difference to us. There's an old saying, "you get more bees with honey." If you take your MBP in for service in person, being as nice as possible goes a long way.

<< this laptop is fairly new, not even a year old. >>

if accurate, it would be covered by Apple's generous one-year warranty on the display (EXCEPT for broken glass not covered).

your picture shows an open Spotlight search window, identified by the magnify-glass icon. Clicking outside that box should dismiss Spotlight and return everything to normal.

if there is a thick vertical box showing, I am not seeing it.

Look, I truly hope for a good outcome for you. And I do understand the frustration. I just find it interesting when people say "if i have to pay for another display i swear to never buy a macbook again." That doesn't help you in any way, and I was more advising you to go to Apple without anger or threats.