Do you have any idea about better cooling
The best advice I can offer would be to turn off your computer and leave it off until you can find some good thermal compound. A small container of first class thermal compound (Arctic Silver 5, etc.) costs less than $10, and your question suggests you don't have the required experience in chemistry to cook up a batch of anything really effective.
When you apply the thermal compound, start by cleaning off all residue from the old compound. Windex works very well to do this. Remember, thermal compound is intended to fill microscopic gaps between the surface of the heatsink and the chip so you want to apply the thinnest possible coat to the cooling area. Anything more will impede thermal contact, not improve it. I usually put a small BB size drop on the mating surface of the chip and use my finger to spread it evenly.
Windex removes it from fingers, too.
Meanwhile, get a can of compressed air, and blow out any dust in the HS/fan assembly, along with any other dust collected in the case.