Low FPS in game, when GPU is overclocked even slightly games freeze up and crash

[TheOriginalGeek]

Okay, this is my first time creating a thread so i'll start with my specs

CPU - Intel i5 4670k
GPU - AMD MSI HD7950
PSU - ******** 600w ATX
Motherboard - Gigabyte GA-Z87-HD3
RAM - 8GB Crucial Ballistix sport

Bare in mind this PC was built 5 years ago and I know it's not the best to begin with, however I know it's capable of more than 10 fps in The Forest.
My issues started recently when a sloppy hard drive was weighing my PC down. It was a slow drive so i decided to uninstall it from my PC, after doing so I decided to give my PC a thorough clean out. I dusted my PC completely, added new thermal paste to my CPU and organised my cables. After doing so I loaded up my games and noticed my GPU fan was roaring. I decided to download a GPU tracking software to understand what was happening, I noticed that my games were crashing when my GPU reached roughly 70°C. I decided to take apart my GPU to get rid of all dust on the card and the heat sink, I also added new thermal paste to my GPU. This seemed to make no difference, I fidgeted about with the Radeon settings and core clocks in an attempt to reduce the heat. This also made no difference.

I feel as though i'm at a dead-end but have no money to invest in a new card. HELP! https://www.************.co.uk/forums/images/smilies/frown.png

 

[TheOriginalGeek]

I have purchased a new PSU (Thermaltake TR2 S 600W) And i am still getting the same problem :/

 

[TheOriginalGeek]

Yeah, this is happening all across the board, whether overclocked or not :/ I'm starting to think that my GPU is dead to be honest

:edit: And no I had not changed drivers before this became an issue. I have tried removing drivers, rolling back and still no change :/