I had PUPPS with my first pregnancy. It was NOT pleasant! Luckily, I was much closer to delivery than you are. Some things that helped were:
Oatmeal baths
COOL compresses -- whenever I got warm, I was miserable. So cool baths, cool rags, ice packs on my hands
As little clothing as you can get away with - nothing tight or binding - that seemed to make it worse
I also had the rash on my hands and feet. Those were the worst places! You can take Prednisone, and for some people that works - it didn't for me. Benadryl can also help, but I'm intolerant to Benadryl. It is, however, completely save in pregnancy.
Good luck and hang in there.