Barbi-girl, You can't wait until May for further treatments. If you are as bad as you say, a more urgent call to the neuro and/or a trip to the ER is in order. As these guys have said, if IVIG is not working, there are other treatments to try. Plasmapheresis can be done in the hospital.
Don't get to a point where you can't do anything (like even dial 911!). You need immediate care. Did you tell your neuro how badly you are doing? Some people need IVIG more often, or another treatment. To just drop something without adding something else is fairly dangerous!
Sometimes it helps to have another person speak for you. That might scare the doctor into action!

But don't you be scared. Just get the help you need NOW.
I hope they can find a regimen that works for you!

Annie