@Luckyswazi
What thermal paste did you use and how did you apply it? A lot of thermal pastes that are popular on desktop CPUs can fail and start to pump out in as little as a week when applied direct die to a mobile CPU. MX-4 has this reputation. Try using Honeywell PTM 7950. It seems to work well for most users long term.
If you cannot improve your cooling then you can use ThrottleStop to slow your CPU down so it does not get so hot. Post screenshots of ThrottleStop including the FIVR and TPL windows so I can see what settings are available to you. Intel has removed access to CPU voltage control in their H series processors so the adjustments available are limited. Next time you buy a laptop, look for one with an HX processor. The 13900HX is a fantastic processor for enthusiasts. The 13900H, not at all.
You can try lowering the Speed Shift Max value in the TPL window to slow your CPU down so it does not get so hot. A better method is to adjust the turbo power limits in the TPL window. No point in having the power limits set sky high to 200W if your cooling can only manage 50W.