Hi, Cindy,
You've chosen a great part of the Vdlp, and I think it's very possible to reach Santiago from Salamanca in 20 days. Starting from Zamora would cut 2-3 days off the total, but most of the "standard stages" show 17 days from Salamanca to Santiago (via the Sanabres, which goes through Ourense, and which I would highly recommend!).
I don't know of any support teams on the Vdlp, if by this you mean backpack transport. But you should know that this forum is about the best support team in the world for any pilgrim trying to get anywhere!
Jitters are a normal feature of any camino. I've been walking every year since 2000, and I still get them. But once you put one foot in front of the other as you start your camino, those jitters magically disappear!
Buen camino, Laurie