oh you poor thing I COMPLETELY sympathise for you because I had that in the last 3 weeks it drove me INSANE it is SO BAD...... I was in agony with it one night I was going insane trying not to scratch it and had to keep having cool showers (thankfully it was summer!!) that helped but as soon as I got out of the shower the pain was back!! I had that PUPPPS rash.... ( cant' remember proper name of it).... it was just awful. One night was so bad i kept waking and DH had to sleep in the spare room I was annoying him with waking up so much (don't blame him!) and kept having showers.
I rubbed almond oil too that didnt help me either. I used to put ice packs on my tummy to relieve it and cold wet towels but besides that, i just waited for it to pass.... it was real bad for about a week or two then stopped.

I was going to use Calamine lotion but couldn't find it! Oh thats right I did go to the chemist and ask for an ezcema (sp?) type cream for itchiness that did help but not really much..... try that perhaps? cant' remember what it was called but just ask a chemist.

Great news is once you go into labour it will stop not long now..... good luck.