Barb!
YOU are NOT a failure!
You are also NOT alone in this!
No drug works for everyone, not even aspirin!
There's a LOT of stuff in the pipeline and new information is coming out even as we speak.
Some of us just get lucky when something works, for however long it works. Others run through the med cabinet a little faster. If Tysabri stops working for me, I will move forward and find another treatment, as you have done and are doing now, as others have done before you.
If one drug worked for everyone, we would only have one treatment and this would be a fairly boring place!
Hang in there, hang with us and we'll hang WITH you!