I realise you want some certainty right now. But you are not in a position to understand your true finances at the moment.
Take a deep breath. He isn’t asking for the house to be sold or for anything to be settled just yet. But there will come a time when you both have to deal with the end of your marriage. And whilst it is better you do it sooner rather than later, don’t rush head long into things.
If taking over the ownership of the house is a goal you need to do it properly. As long as you remain married and don’t have a financial order agreeing on how your marital assets are split he can make a claim. Even if you take over the mortgage and he says you can keep it. To be home and dry you need the court order.
Things you need to resolve include what exactly you both own that needs to be split. That’s all the savings, pensions, equity in the home and any debts.
Then you need to resolve how these assets are split. It can be anything you both agree on. As long as you show you made the decision in an informed way. This means you both take legal advice and you know what the assets are.
If you have to negotiate the split of the assets you will both need to work out your needs. You will both need a home and pension provision. If there isn’t enough to provide a home for both of you then you may need to get a mesher order to stay in the family home. Note a home can be a rental if that is affordable.
As attractive as a mesher order sounds they come with significant downsides. This is why they are an option of last resort.
As part of establishing the split you need to what you can afford. For this you need to know your income, salary, benefits and any CMS. Although it is always better to not rely on CMS