all:
diffident.
certain, assured:
depressed,
uncertain,
weak,
shy,
sad,
indefinite,
unsure,
pessimistic,
meek,
timid,
cowardly,
afraid,
doubtful,
fearful.
noun:
indecisive,
Self-reproving,
unassertive,
bashful,
incertain,
incapable,
quiet,
reserved,
overmodest,
vacillating,
wavering,
hesitant.