What happens if I don’t make the minimum required income for my healthcare subsidy?

Edit: Living in Alabama

I signed up for a marketplace health insurance plan back in December with AV 94% cost sharing reduction under the Affordable Care Act. However, I don’t think I’m going to end up making the income I expected this year, so I’ll fall under the income threshold (I think it’s around $13k?) to be eligible for the premium tax credit.

My question is — what happens if I don’t hit the required income level? I can’t afford my plan’s premium at full price and I’ve been paying monthly at the reduced rate.

I was hoping you all could answer these questions:

Am I going to owe back thousands of dollars if I don’t hit the required income amount?

If I do owe that money back, will I owe it immediately, or can I make a payment plan?

Will failing to meet the income threshold negatively impact which health insurance plans I can qualify for in the future? Will I never be able to be eligible for a premium tax credit ever again?

Are they going to come after me to investigate why I didn’t make the income that I reported I would make? I wasn’t deliberately trying to be dishonest but I don’t know how to prove that.

I’m panicking so I would really appreciate your answers.