Your meeting with your H is tonight. I just wanted to check in and say that I am thinking about you. It sounds like you have prepared what you wanted to say, what your boundaries are, and what kind of behaviour you will put up with, or not, from him. You've done all you can.
If your H is anything like mine, when he feels pressured by the facts of a situation (he is going to either have to contribute to the mortgage or agree to sell the house - one or the other will requite his involvement, there's no other way) he tends to blame the messenger and kick up all kinds of diversionary tactics to move the conversation onto some fault with the way the message is being delivered, the timing, the tone of voice, whose fault the situation is, etc. Anything other than just sit and say what he wants and what he is willing to do. Your H might not be like that (though I winced when you described him putting his hands over his ears and singing) but you might have a think about what your plan B) is. What do you want? What are you willing or able to do if he refuses to get involved? I guess you can get a court order to sell in the event of a divorce. That might be a nuclear option, and might be the only one you have. Could you take in a lodger or AirBandB one of your rooms? I know that having a rough plan to respond to a worst case scenario helps me stay calm in the moment of these types of conversations.