Are you single and filed an individual tax return, or married and filed a joint tax return?
No, to both. I didn't file a tax return yet.
What if I earn a lot less money now and fulfill the requirements for a new decision?
In that case we need to see documentation verifying the event and the reduction in your income. The documentation you provide should relate to the event and may include a death certificate, a letter from your employer about your retirement, or something similar.