If you have a cheap headset mic, there is nothing you can do about it. Cheap mics deliver crappy quality. In general avoid headsets with mics and get better audio equipment. If you are on a budget, these are the best you can get at a low price:
Get a USB Audio interface with +48V phantom power
Replace headphone XLR mic cable with a coiled XLR cable
Buy a higher end XLR mic cardiod condensor
Buy a better pair of headphones
You can also replace the headset mic with a better set of mic. I've used these Antlion's with a set of Beyerdynamic DT 770's and wasn't thrilled with them. You will have to use Krazy Glue to keep it attached to the headphone as I've found the sticky tape never worked well and made the mic always fall off.