Two weeks is a long time to be treating a rash yourself, especially if it is not getting better or possibly even getting worse. Therefore I highly recommend that you make an appointment with your primary care doctor
to get the rash looked at.
It is possible that, as you say, this rash is just a heat rash, which is caused when skin gets irritated by friction and sweat and dirt. In this case, keeping the skin clean and dry should do the trick. However, you have already been doing this without much effect.
Therefore, other possibilities need to be considered. The most likely is that you have developed folliculitis. Folliculitis is an infection of the skin that occurs at the base of hair shafts when bacteria invade and begin to replicate there. The symptoms are red, raised areas around the hair shafts that may develop whiteheads or even abscesses. Although mild cases of folliculitis can be treated with simple skin hygiene, more advanced cases may need topical or even oral antibiotics prescribed by your doctor.
If you are experiencing severe pain, or if there is any large area of firm, red, raised skin that is warm to the touch, these may be signs the infection is worsening at that you would need to go to the emergency room.