OK, I got poison ivy really bad one summer. I mean really bad... it was all over my body practically. My face was swollen along with my hands, arms, and legs. I oozed a lot. Great fun. Here is what I did... I went on prednizone (prescription steriod) and zyrtec. The drugs really whacked me out, but they helped speed up the healing process for my body and provided some relief. Also, get some plain Benedryl (over the counter, you can go generic) and take it before you go to bed every night. It will provide itch relief and help you sleep. For the first week, I would wake up in the night itching and would have to take another two pills. Also, be sure and wash your bedding every few days to get rid of the oozing and oils that will cause further irritation. Finally, for the really bad spots, you could try some maximum strength cortizone cream.
That all being said, I would also get some over the counter stuff called "Oak and Ivy" (maybe Oak n' Ivy). From what I understand, it works wonders.
Finally, I respect your desire to treat the poison ivy with natural remedies. I would have done the same thing, but the rash was all over the place. I could have easily itched my face during the night and spread the rash into my eyes. If the rash gets bad, don't mess around. Get to a doctor.
Ryan