Fiver or so isn't that bad... https://www.overclockers.co.uk/air-cooling/cooler-accessories/thermal-pads
I put it back together, and it ran a benchmark for a while before crashing. I realised that my global wattman settings had reset. I put frequency at -7.5% and set a more aggressive fan profile. I will try gaming later tonight. Playing Subnautica for 42 minutes with a stable 62C and a max 64C. I bumped my speed up to -5% and it went up to 63C an a max of 67%. I set CPU overclock to 4.6 and things look good.