When you are waxing, apply wax in the direction of hair growth and wax should be tolerably hot. Then try to wax the hair out in a single strip as multiple strips may injure the skin more. After waxing apply ice(wrapped in a towel) and some calamine lotion on the skin which helps in soothing. You can also take some over the counter anti-inflammatory like ibuprofen after waxing.
However, the best method of painless hair removal is by laser treatment. I would advise you to consult a dermatologist/cosmetologist and discuss this option with him.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.