If its realy broken it is esyer to just get a cheap air cooler.
You can first try remounting it and check if everything is proberly attached. And try all the different fanheader on the mobo.
Looks like its older.
Are you sure your pump is running? You can try different fan headers for the pump and fans.
Also try to adjust the fancurve in the mobo settings.
Since it shutsdown so fast its most likely that your pump is broken. You can try touching the cpu block and try too feel if there is anykind of movement / vibration. If not is most likely dead.
I had the same after a bios update on my MSI board. After the update completed i just got a black screen.
I downloaded the bios again and used the bios flash button.
After that everything was fine
I said try diffrent settings in AA
AA does much for Hair,Trees,Grass usw in Red Dead
Try out diffrent TAA, MSAA,FXAA settings and try diffrent combinations with Internal resolution scaling.
What you like best you have to find out yourself THIS
If you search for the number on the vram K4G41325FE-HC28
you get 4 Gb Density so i say its a 4GB variant you have there.
The 8GB variant shoud be K4G80325FB-HC25 i believe.