Im really lost as I have tried so many things now, first my machine wasnt booting when it first died, then i removed an nvme on which i had a hunch and then was able to boot to my windows(dual boot system) and see temperatures were soaring, its almost 3 years since i bought it and havent repasted so i thought that might be the problem. Got it repasted but still temperatures are all over the place, 40-60 °C(cpu) idle to minimal load and 40-55 °C(gpu). The problem really starts when I run something cpu intensive, the temperatures for the cpu soar and even cross a 100 °C and core throttling is enabled which i can see on HWiNFO, though the system doesnt shut down there from what i have observed. It shuts down as soon as I run something GPU intensive like a benchmarking or putting on Dying Light(1) on high settings. It sometimes instantly shuts down the LCD display along with the HDMI(whats goin on?!), system remains on for some time as audio is heard and then it hangs. In the other case if the system doesnt shut down the GPU goes into high temp mode as well, like above 80°C which wasnt the case before. I used an Arctic MX-4 to get it repasted but although it was never opened it was sitting in my drawer for more than 2 years, could that be the problem also? I also found out that a RAM slot was shorted or something as the RAM inside it didnt work in any other slot and the slot didnt accept any other RAM stick.
I also changed some settings through my Alienware Command Center to make the games work and not let the machine shut down/hang, following are the values:

Game: Dying Light 1 || Settings: High
AWCC with "Cool" thermals and undervolted OC custom profile:---
CPU temp: 50-75°C || GPU temp: 45-65 || Frames: 25-35
AWCC with "Balanced" thermals and OC off(regular mode):---
CPU temp: 90-101°C || GPU temp: 75-85°C || Frames: 80-115
As visible above, if the display doesnt shut down the numbers are really bad in terms of frames in the low config and really bad in terms of temps on regular config. Dont know what the heck is goin on esp when display turns off, else the laptop runs ok on normal load with my work n stuff.

System:
Alienware Area-51m R1
i7-9700k
20GB (24 previously)
GeForce RTX 2060