After you file

I am trying to amend my 2018 TurboTax online return. I have saved my original return.  When I log into my return and select to amend, my Federal Refund figure drops to 0.  My Illinois state tax figure goes to $319 tax due althoughI actually received a refund from the state. 
Entering the federal tax section, Wages and Income, Business Items section, Business Deductions and Credits, Visit All, Self-employment health insurance paid, start, continue, update, I am simply taken in a circle of prompts. I am not able to actually update any figures. 
I am at the point of giving up on TurboTax.