38 weeks pregnant and in soo much distress :(?

i have a severe rash all over my arms, legs, feet , hips and bum!! been to the docs twice and all the creams they have given me irrate it im booked in for a blood test tues and have midwife the same day a week before im due!! which is how long u have to wait for the results.. i have been stuck in my house cos the the heat and clothes irritate it, im currently smothered in natural yoghurt to try 2 reduce the soreness its making me even more emotional and stressed, just wondering if anyone has had similar problems and what they done to help the problem? first pregnancy and at this moment in time its going to be my last .........