It is too late to work an amendment to get any amounts refunded, but you may be able to get future payments eliminated/reduced. You or your representative may need to contact the Marketplace.gov customer service to get an approved exemption. They may provide you an Exemption Control Number. A hardship exemption is for the month prior to the hardship, the months in the hardship, and the month after the hardship. The Marketplace reps should help you figure all that out. With an approved exemption you or your representative may be able to contact the IRS to help going forward.
Here is a link with more details on the hardship exemption for 2018 and before.
Here is a contact number (800-318-2596) and there is also a "connect with us" section near the bottom of the linked page with contact information for assistance.
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