Why is my processor burning?

[Ceddyhmra]

So basically my processor is way to warm. It will get like 90c when playing gmod. I dont even dare to play games such as GTA V. It has the stock cooler, I have already bought the available water coolers where I live but none of them did fit in. Its around 60c-70c when idle.
My computer case is very cold though. Is there any way to fix this? How long will my processor survive?
I dont really expect an answer. I wrote this beacuse im bored. I would appreciate an answer though.