I had the same concern as the house was in husbands name only and he owned it before I met him. I went to Citizens Advice to find out my rights and was referred to Legal Aid. I was told my CA that I could register my home rights to protect my interest in the house and in the end, I ended up with 65% of the assets, including the majority of equity in the house because of each of our own earning potentials.
My Legal Aid solicitor registered my name to the property for me and it protected me as ex tried to refinance the house secretly to pull out all the equity and was stopped as I had to sign off on it before he could. Ex had no idea I was entitled to 50% plus of assets and had tried to get me to move out into a bed sit the same day I found out about his affair.
You need to find out what you are legally entitled to and what he can and can't do, such as changing the locks (neither can).
Start keeping a diary of what is going on such as threats, nasty comments, financial abuse or any other issues. I kept mine in my Yahoo email so he couldn't find it in the house.
Also, get copies of marriage license, any bank statements, find copies of income statements and pensions.
Change all your passwords to social media, bank accounts, phones, etc.