Flickering lines on my macbook screen

I purchased my MacBook, 3 years back. I'm an Architecture student and I purchased it in my initial year of Architecture. Towards the end of first year with a lot of work on Mac, I found few horizontal lines on top of my screen, I got scared and gave it some rest, and later it worked fine. The same happened much later, towards the next semester end, and it started progressing, as I continue working on the Mac.

So I realised my Mac works completely fine, when I'm using it to watch movies or to browse, or for any normal usage, but when I use softwares like photoshop, cad, sketches etc, for long hours, that's when the flickering starts, and it progresses until these lines fill up the whole screen and starts flickering, and you can't see anything anymore. I started getting an idea of this issue, by the time I was in my end semesters, and now there was a lot of work on softwares than earlier. By the time I was able to identify this issue, I ran out of apple warranty period. And now when asked to change my display, it's very hard for me as a student. I'm greatly disappointed as Mac is an expensive product, and this is just really disappointing. While I'm able to use it smoothly for other purposes, its hard for me to be able to work on it as per requirements as a designer. While there have been some display related programs free of cost for the other models, there's not one for the 2017 MacBook model.