Synonyms for Trying:

adj.

difficult (adjective)
adverse, cantankerous, complex, complicated, contrary, cumbersome, demanding, difficult, finicky, formidable, fussy, grinding, hard, harsh, knotty, laborious, onerous, rough, rugged, strenuous, stressful, thorny, ticklish, tight, toilsome, tough, tricky, uphill, wearing, wearisome, wearying, arduous, bothersome, burdensome, oppressive, severe, troublesome.
difficult, bothersome (adjective)
aggravating, annoying, arduous, demanding, exacting, exigent, hard, irritating, onerous, oppressive, rough, severe, strenuous, stressful, taxing, tight, tough, tricky, troublesome, wearisome, weighty, Irksome.
effortful (adjective)
effortful.
nerve-racking (adjective)
stressful.
painful (adjective)
aching, acute, aggravating, agonizing, annoying, arduous, biting, bitter, bothersome, burdensome, chafing, cruel, crushing, cutting, disagreeable, distressful, excruciating, grievous, grueling, harrowing, horrendous, hurtful, inflaming, insufferable, irritating, miserable, odious, offensive, oppressive, painful, piercing, severe, smarting, sore, stabbing, stinging, throbbing, troublesome, unbearable, uncomfortable, unpleasant, withering, woeful, wrenching, Besetting, Gnawing, Irksome, tormenting, Cramping, anguishing, Torturing..
vexatious (adjective)
irritating.
weary (adjective)
apathetic, blue, bored, cheerless, debilitated, depressed, droopy, drowsy, exhausted, faint, fatigued, feeble, flaccid, footsore, limp, listless, sleepy, tired, wasted, weak, weary, worn-out, Wayworn, Frazzled, run down, over-weary, toilsome, uphill.

n.

hypnotic, soporific. backbreaking, effortful, exacting, exigent, heavy, rigorous, taxing, weighty. troublesome (noun)
tiring.
trying (noun)
difficult, disagreeable, hard, nerve-racking, nerve-wracking, stressful.

v.

experimenting (verb)
determining, investigating, probing, testing, verifying, Analyzing, Assaying, Checking, Proving, Benchmarking, experimenting, researching.
punishing (verb)
avenging, chastening, confining, distressing, executing, judging, punishing, Afflicting, Burdening, Castigating, Chastising, Disciplining, Fining, Imprisoning, Incarcerating, Keelhauling, Persecuting, Pillorying, Sentencing, Correcting, Crucifying, penalizing, lambasting, reprising.

Other synonyms:

backbreaking, effortful, tiring. hypnotic, soporific. exigent, rigorous, weighty. exacting, taxing. heavy. Other relevant words:
backbreaking, effortful, exacting, exigent, heavy, hypnotic, nerve-racking, nerve-wracking, rigorous, soporific, taxing, tiring, weighty.

Usage examples for trying

  1. I have been trying to think." – Hills of the Shatemuc by Susan Warner
  2. " I'm trying to," I said. – Jack of No Trades by Charles Cottrell
  3. I was trying to remember all night. – Madge Morton, Captain of the Merry Maid by Amy D. V. Chalmers