Nannie,
Auto-immune condition will often cluster. What I mean is, it is not unusual for someone with an auto-immune condition to have more than one. The thing with ITP is that no two cases are the same. We all have low platelets, but everyone responds to treatments differently. That's why there's such a smorgasbord to choose from! Unfortunately there is no fail-safe treatment. And, as you well know, a treatment that seems to be working very well can stop working overnight.
I often feel like some sort of cosmic experiment. Just when things seems to be settling down, and I am getting back to "normal", someone changes the paramaters and everything goes "wonky".
I know this isn't very comforting, but I just wanted to let you know that you're not alone in this. The "ITP Roller Coaster" is just as much a mental ride as anything else.
Blessings,
Hauna