Vertical lines and weird crack UNDER screen on MacBook Pro 15"

Hi. It's my first time writing on here. Here's my story:

It all began in late 2014 when I purchased my first MacBook product - a mid-214 MacBook Pro 15" with Retina Display. For those who want to know the full specs, it has a Core i7 2.2 Ghz with 16Gb of RAM.

Now, everything was fine until later in 2015. My screen started ghosting. When I closed an app, the content "stayed" on the screen, but faintly. Almost like a ghost of the last page. Sometimes it did that, sometimes not at all. I went to an Apple Store, showed some photos and succesfully got a free repair. I was still under warranty.

Later that year, with the new screen, weird grey lines started appearing from time to time on my screen, it almost looked like a grid, every line was spaced by 3-4 pixels. The lines were horizontal AND vertical. I didn't go to the Apple Store until 1 month later because I was in my finals and I could use the computer even with the weird lines. Unfortunately, at a point during that 1 month, I opened my computer to see a weird crack in the bottom left of my screen, and black and white lines coming from it. My heart stopped beating. I checked with my finger to feel the crack, but felt nothing. I thought that was really weird. I immediately took an appointment to my Apple Store. Bad luck #2 : When feeling the crack again, I actually cracked the screen itself. Trust me, I wasn't pushing hard AT ALL. I barely TOUCHED it. Anyway, when I got to the Apple Store, they said that it was my fault and that I must have left a pencil or something under the screen when I closed it. I was forced to pay the repair by myself. Fortunately for me, I stayed and talked to the manager, and he accepted to reduce the price to half of it. (~350$ CAD) By the way, I was still under warranty. Now, I was back with a working MacBook and was happy (after all).

Time travel to this morning. The same thing happened, but without the weird lines before. I just opened my laptop to see the crack, IN THE SAME PLACE! It's still UNDER the screen since I can't feel it. But now, the screen flickers every 1-2 seconds and big lines appears and block the entire screen (see video). It's not even 1 year since the last repair. Is there a warranty for repairs? If so, how long is it? Also, could they do it for free? I can't afford to pay another time for a screen. It's not cheap at all!

What can Apple do?

What can I do?

Here's the video of it flickering : https://youtu.be/n59En4t_mBE

TL;DR: My screen was replaced 2 times for the same problem. Now, the problem reappeared, but I'm out of warranty. What can I do?

Thank you for your time,

Jeremy