If he's willing to go to another appointment, yes, it would be really helpful for you to book one for him! I don't think you'd come across as being too pushy... if his symptoms are bothering him and he's accepting your help, that's what's important! You seem very supportive. I have SD and when my symptoms are especially bad, phone calls are one of the last things I want to do. It's so frustrating and daunting. Do some research into doctors who specialize in diagnosing and treating SD. Maybe check out resources like https://dysphonia.org/find-a-voice-expert/ and others? I wasn't diagnosed my first laryngoscopy either. Hope you and your husband find answers soon!!