Could it be schizophrenia and now the positive symptoms (hallucinations, delusions) are controlled with meds only the negative symptoms are left (flat affect, poverty of speech, inability to experience pleasure, lack of desire to form relationships, and lack of motivation)? The negative symptoms of schizophrenia are basically the same as schizoid personality from what I understand, which is why schizoid is on the "schizophrenia spectrum".

I thought schizoid-like symptoms (negative symptoms of schizophrenia) with prominent hallucinations/delusions (positive symptoms of schizophrenia) would be considered schizophrenia? I'm not saying your psych is wrong, obviously he's more qualified and knows more about your situation...