Laptops usually do not have the best cooling in the first place .. AT least not good enough to support OCing, which creates even more heat and stress.
Are the issues the result of an OC attempt, or are you trying to OC to resolve them?
OCing will only cause more headaches and issues, and possibly permanant damage at this point.
I agree with Terrronium 12, find & solve the problems you are having.
One suggestion would be:
Try to clean it out real well, with a can of compressed air. Could be some dust build up.