MacBook Pro mid-2012. Multiple issues.

I've had a few severe problems laying around my MacBook mid-2012, I just wanted to submit them here to see if I should visit the Genius Bar or if I could do anything to better the situation. I am a first-year in uni so I don't really have the financial means to fix anything even if I do visit- so I'm kind of piecing things together, hoping they work.

A few days ago, I noticed that my laptop was overheating while sleeping. I found my laptop warm in my bag when it would've been sleeping for a while.

Then I experienced the barcode-like glitch + freeze + reboot. Was quite startled. I noticed I got this especially when squeezing the bottom-left side of my keyboard.

MBP 13” Display Glitches - “barcode freeze” - SOLID WORKAROUND FOUND

I read this thread, decided it was a good idea to do what was suggested, taped some coins covered with electrical tape, stuck them in there.

The thing is, after that screen glitch, seeing that it was most likely a RAM issue and not having the screwdrivers to open the back panel (the screwdrivers arrived today), I shook the device around a little bit, hoping that would do something. After doing so, my three beeps stopped and the laptop tried to boot.

However, every time it tried to boot, it would just shut down (without any noise- it would quietly power off) halfway through boot. Like, just, half-way. The startup chime rang fine, I've tried resetting the PRAM and SMC; it was weird, after all. This seemed like a different problem.

And then the diagonal-line-through-circle popped up. Which meant, the laptop could not find a bootable hard-disk. I tried pulling the disk out, putting it back in. No avail. It's dead, as far as I understand.

It's kinda bizarre how this happened all at once and it escalated so far. It's only been a maximum of 6 days since I've noticed my laptop was overheating. I'm bummed I had to lose a hard disk like this but I still have hope that it might be alive, I don't have that important of data in there but I have three years worth of pictures.

Right this moment, I'm using my external hard disk to boot from, along with taped up ram-slots. The laptop seems to be running fine. I'm writing this thread on my laptop after all. Do you guys think I'm good on my way? What could have been the problem? Should I be worried about my disk?

Thank you so much for reading a rant-y question-y thread, and hope you guys have a great weekend. Cheers.