Rather than use soap because that could irritate it more use sorbolene cream to bathe it. I don't know if you have Savlon cream over there but it's fantastic. It's an antiseptic cream but is also good for inflammation. I am never without a supply.
You could have swimmers itch go to your doctor and they will be able to perscribe you with cream to put down there or you can even try zinc wich you can find in the baby section it might get rid of the rash burn
I'd use Neosporin or just a good emollient skin cream.
the thing is that it hurts to even wash! i did wash with soap b/c i hate feeling dirty down there. do you know what type of ointment? i just want it to help it heal faster! thanks
Soak in a tub to be sure you have all the sand out of the crevices, then put on some kind of soothing ointment. It should heal pretty rapidly.