Dear Eva,
As far as being "...afraid of getting scared" as the surgery date approaches, I think myself that anyone who is NOT at least a little scared probably does not understand what is happening. Kidney donation is relatively safe, but it IS major surgery, and there ARE risks. Some donors go through with it feeling little or no fear, but most I have read of certainly said that they felt fear, and some have shared their experience of becoming nervous wrecks in the days leading up to surgery. Everyone is different. Wanting whole-heartedly to donate, and at the same time feeling scared, are not mutually exclusive.
Please let us know how things go.
best wishes,
Fr. Pat