Welcome to HW.
It would be best if you start a new thread, and give us your PCa background, so that guys with similar experience can chime in to help.
I would say that going from 20 to 30 in one step could be very risky. My uro advises steps of no more than 10%. For me, a change from .10 to .13 was enough to generate a departure for the emergency room.
Did your Uro work with you on the first injection, and coach you on method & amounts?