You can control the fan using
You can control the fan using either motherboard BIOS settings (if your BIOS supports it) or a program like SpeedFan. The problem with this approach in your situation though is that if the fan is speeding up under load, it is necessary to cool the CPU down so preventing that from occurring with altered fan settings will potentially damage the CPU.
That means you really need to get a better cooler. I generally like tower style heat sinks with big fans since they can spin slowly and still keep the CPU cool. Depending on your case, there may be some size restrictions. Also, if going with a tower cooler, there is usually a backplate to sit against the motherboard to prevent flex and help support the large cooler. This means you either have to have a cutout access to the back of the motherboard or will need to remove it for installation.
There are other options too. You need to understand what your case can support and whether you want one with backplate or push-pin.