Hi Toffeeapple,
Thank you for sharing with us. I hope it is helping to post on the forum. It might be helpful to find out your rights and options in regards to your husband changing the locks. You could contact Shelter line to discuss your housing rights. Shelter line offer free and confidential housing information, support and legal advice on all housing and homelessness issues. They have a live chat service, and an emergency helpline available on 0808 800 44 44 (8am-8pm weekdays, 9am-5pm weekends). Their website has a lot of useful information.
Best wishes,
Lisa