the problem is you can't make the non-deductible IRA contribution to begin with, above the amount of your earned income, which as you agree is zero; so then you can't move it thru the backdoor conversion to Roth if it was an excess contribution to the IRA. For every year you don't fix the IRA issue you get a 6% penalty.
I don't know all the mechanics of how to resolve this, but wanted to reply that you definitely have an issue to resolve before filing, you may even get delayed and need extension to October. The good news - I think - is if this all happened in 2024, you may be able to avoid the penalty(ies) if you undo all this before the tax filing deadline, and you may just have some tax due on earnings that happened during the whole process. Hopefully you didn't do the same thing for 2025 yet.
I don't know all the mechanics unfortunately, you may need to recharacterize the conversion back to the IRA to unwind the 1099-R with the custodian/broker, then withdraw it from the IRA. Hopefully a CPA/Expert will respond here to provide guidance. Try searching on here for various threads on excess IRA or Roth contributions/conversions but every situation could be a little different, also you should talk to your broker.
You may also want to search/post this over in the 'Retirement' forum which is more focused on these type issues.
Maybe @dmertz @BillM223 @VolvoGirl can help further
