Excruciatingly

Adverb

 * 1) In an excruciating manner or to an excruciating degree; in a manner causing great pain or anguish.
 * The gunshot wound was excruciatingly painful
 * 1) In a very intense or extreme manner.

Thesaurus
abominably, agonizingly, awfully, baldly, balefully, bitterly, blatantly, brashly, confoundedly, cruelly, damnably, deadly, deathly, deplorably, deucedly, distressfully, distressingly, dolorously, dreadfully, egregiously, excessively, exorbitantly, extravagantly, flagrantly, frightfully, grievously, harrowingly, heartbreakingly, hellishly, horribly, improperly, inexcusably, infernally, inordinately, intolerably, lamentably, miserably, nakedly, openly, painfully, pathetically, piteously, pitiably, ruefully, sadly, shatteringly, shockingly, something awful, something fierce, sorely, staggeringly, terribly, torturously, unashamedly, unbearably, unconscionably, unduly, unpardonably, woefully