Suggest Treatment For Breathing Problem While Having Nicotine Lozenges

My husband (a physician) age 67 believes he has a low tidal volume and is afraid he is dying. We just came home from the ER where he was diagnosed with anxiety; he was prescribed Vistaril, and he has taken one. But he insists the anxiety is caused by fear of dying from low tidal volume. He is also in withdrawal from nicotine lozenges which he has been taking for ten years. He took 2 bupropion tablets a few weeks ago to help with nicotine cravings. He thinks the bupropion has permanently bonded to his nicotine receptors because now no matter how many nicotine lozenges he takes, he cannot quit craving and he is in withdrawal. He thinks the breathing problems now are permanent and that he is dying. We have been to the ER twice, and his regular doctor knows what's going on, but my husband needs help and we don't know where to go.