Poison ivy is no fun and I'm so so sorry that it's so bad Bizi. I'm so allergic I get it in my eyes if the wind blows. So I feel your misery.
Believe it or not, Windex seems to be effective. I saw that in My Big Fat Greek Wedding . It doesn't dry the rash but it does stop the itching for a while.
Feel better soon. Hopefully the steriods will kick in.