Deductions & credits

Correction: The amount TT says I owe is $5465!!  

Can anyone explain why / how entering ACA data (1095-A) can take you from a >$1K refund to a >$5K deficit owed?!  I'm totally confused.  How do I avoid this for next year? 

I'm going crazy with this.  I'm retired and don't just have $5K in my pocket. 

Thanks for all / any help!

Pete