What happens with my H-1B status if the company I work for goes under (hypothetically) or if gets sold? What are my options?

Those are two very different scenarios. If the H-1B sponsor ceases to exist and you accordingly, no longer work for them, you will no longer be in valid status. If the company is sold or taken over, depending on the nature of the transaction, amended petitions by the acquiring company may or may not be necessary. The acquiring company's immigration counsel will need to make that determination based on the nature of the acquisition.

Look for another job if you believe you will lose this one. If the company is bought out, then the new company can petition to take over employees.

If the purchasing entity does not rehire you and amend your petition, you have to go home.