1) very worried (concerned)
2) a question or problem that is difficult to understand or answer; a game, toy etc designed to test a person's knowledge, skill or patience; to cause (a person) to become confused, worried (about the solution to a problem) (puzzle)
frightened
fearful
extremely troubled or upset
very upset, worked-up
of the nerves; easily afraid, timid
anxious, fearful
too anxious
tense
(of the stomach) easily upset; (of a person) feeling sick
not feeling well; not comfortable
never still or quiet
not content; moving about
without sleep
insomniac, restless
uncomfortable in body or mind
awkward, uncomfortable
a condition of being ill; an unexpected result; to knock over; overturn; to cause (a person or thing) to be disturbed
disturbed, bothered
extremely tense or nervous
nervous
