Your ex is entitled to move on with his life, which he is trying to do by divorce and having his name removed from the deeds. That's perfectly normal even if it doesn't suit you.
You want to stay in the house and indeed are able to meet the mortgage payments.
It looks like there is no equity in the house your husband would be entlitled to and in any case you've no money to pay him off, but the bank won't allow him to come off the deeds, but I don't think a judge can order that the mortgage be put soley in your name which would be a solution for you both. So the only option the judge has would be to order a sale, but then who is going to pay back the negative equity. Maybe starting the court proceedings and informing the bank of this might focus the banks mind. If your husband has a good job they are unlikely to play ball though.
Judges are going to have to be more inventive for the times we live in, maybe he'll order that you stay in the home and continue with the mortgage and that your husband has no 'interest' in the house, but that still doesn't get the husband off the liability for the mortgage. How that can be solved without the banks agreement, someone wisher than me might have an idea.
What has your solicitor advised you?