WordNet (r) 3.0 (2006):

distressingly
    adv 1: unpleasantly; "his ignorance was painfully obvious" [syn:
           painfully, distressingly]

Moby Thesaurus II by Grady Ward, 1.0:

59 Moby Thesaurus words for "distressingly":
   abominably, agonizingly, awfully, baldly, balefully, bitterly,
   blatantly, brashly, confoundedly, cruelly, damnably, deadly,
   deathly, deplorably, deucedly, distressfully, dolorously,
   dreadfully, egregiously, excessively, excruciatingly, 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