painfully (part of speech: adverb)
grievously, agonizingly, distressingly, gruelingly, excruciatingly, tryingly, tormentingly, aggravatingly, unpleasantly, troublesomely, gnawingly, witheringly, unbearably, sorely, irritatingly, annoyingly, painfully, uncomfortably, woefully, achingly, bitterly, miserably, horrendously, smartingly, piercingly, hurtfully, irksomely, bitingly, offensively, disagreeably, cruelly, odiously, torturously, stingingly, oppressively, acutely, insufferably, severely, distressfully
difficultly (part of speech: adverb)
fussily, stressfully, roughly, harshly, adversely, ruggedly, laboriously, grindingly, demandingly, contrarily, toughly, tightly, strenuously, wearisomely, complexly, difficultly, knottily, formidably, ticklishly, trickily, toilsomely, complicatedly, cantankerously, onerously
- Ever since I have resumed my work in the Holy Land I have been awaiting with eager and particular interest the detailed letters, individual as well as collective, of my loved ones in Germany, who, I am sure are arduously, devotedly and efficiently carrying on the Great Work which the Master has destined for them in this world. - "The Light of Divine Guidance (Volume 1)", Shoghi Effendi.
- The people worked arduously and without intermission; the land was rich, the seasons propitious; yet they almost constantly suffered the pangs of hunger, which spread sometimes to wholesale starvation. - "Irish Race in the Past and the Present", Aug. J. Thebaud.
- In the course of his long and wandering life how often had he been paid off; how often had he felt his pockets heavy with the gold so arduously toiled for; how often had he vowed to himself that this time he would keep it! - "Wild Justice: Stories of the South Seas", Lloyd Osbourne.