Jan,
I can only imagine how frustrating this all must be for you. Maybe getting the PICC line put in is a good thing. It's incredible how fast our bodies bounce back once we're rehydrated again. Maybe you just need the extra assistance the PICC line can give, while you try to work out a plan that will keep you hydrated in the long run.
I'm not too familiar with probiotics, but I do know yogurt is a good source of it.