Did you get a letter from the IRS requesting you provide them form 8962 and the 1095-A? If so, I seriously doubt that letter instructed you to amend your return. What's the form number of the letter you got from the IRS? It's at the top and starts with "CP" or "LTR".
Once you confirm what you got from the IRS, I can help you with this. One thing you will need is the 1095-A sent by the issuer of the health insurance policy, to the policy owner.
Your situation is most common when you the tax filer are not the policy owner. So if this is a case where you are covered on your parent's Marketplace policy, yet your parents do not claim you as a dependent then you *MUST* obtain a copy of their 1095-A from them in order to fulfill the requirements of the letter you got from the IRS.
