tied in knots (adjective) concerned: worried
Sinonime: anxious, biting one's nails,
bothered, butterflies in stomach,
distressed,
disturbed, exercised, in a stew, on pins and needles,
perturbed, tied up in knots,
troubled,
uneasy,
upset,
uptight, worried sick
Antonime: happy, undisturbed, unperturbed, untroubled, unworried