the rates of valtrex/acyclovir resistance in otherwise healthy adults is about 1%, the same rate they were when acyclovir was first developed to treat herpes. You really don't need to worry about resistance to herpes.
you will still have recurrences even while on suppressive therapy. you've actually been pretty darn lucky only having your 2nd one now.
grace
A little more information. I have been on suppressive therapy since the beginning and my recent (2nd) outbreak coincided with another illness (head / chest cold) that was failry bad. Thanks.