My refund disappears when married filing separately

I have 3 children and normally would file as head of house hold. I would also receive a refund each year. In 2018, I married and filed a joint tax return. My refund was taken away from me because my new husband had a massive amount of debt that I didn't know about. I contacted the IRS and they helped me file a injured spouse form and they sent me my refund. Now filing for 2019 I wanted to file married filing separately since my husband has still a large amount of debt. When I was doing the turbotax for 2019 my refund is zero. So I tried to see what it would look like with filing jointly and it showed my normal refund amount. I don't want to file jointly since my husband has so much debt that might take away my refund again. How can I file separately with my 3 dependents and get my refund?