I cannot offer a diagnosis over the Internet but I can provide some insight. Hearing voices is not a symptom of an anxiety disorder. Hearing voices is a sign of possible psychosis. Psychosis is a break from reality. It is a symptom of several mental health disorders, including: schizophrenia, schizoaffective disorder, bipolar disorder and several others.
Drinking to suppress the voices is known as self-medicating. It is a relatively common, though ineffective and dangerous, response to trying to repress symptoms of psychosis. Drinking likely exacerbates the problem. Not only does drinking make the problem worse, it may be contributing to his anger outbursts. Your boyfriend should receive help for his problem.
Encourage him to be reevaluated by a psychiatrist. I also would suggest that you go to the evaluation with him, if he allows. That way you can directly report his symptoms to the psychiatrist. There are medications that can decrease the voices or eliminate them entirely. They are called antipsychotics. Antipsychotic medications are designed specifically to treat the symptoms that he is experiencing. Please encourage him to be evaluated by a psychiatrist as soon as possible.
A word of caution: most individuals who experience psychosis are not violent but the research shows that they can be when under the influence of alcohol or drugs. He has been verbally abusive while intoxicated. In addition, he has no recollection of the event. This is indicative of a loss of control. The mix of alcohol and psychotic symptoms are likely contributing to or causing this loss of control. Don’t hesitate to call the police or the mental health crisis team if you feel threatened.
I hope this answer helps guide you in the right direction. If you have any additional questions, don’t hesitate to write again. Please consider writing back and letting me know how you and your boyfriend are doing. Please take care. I wish you the best.