I made a $6,500 prior year contribution to my deductible IRA on 4/8/19. So this was a contribution for CY 2018 made on 4/8/19.

I extended my 2018 tax return to 10/15/19.

I also maxed out my 401(k) salary deferral for 2018 – so I was “covered by a qualified plan” in 2018.

I file Single.
Turns out, I made too much in 2018 and cannot deduct any of the $6,500 I contributed (i.e. My 2018 MAGI was greater than $73,000.)

So I now want to distribute the $6,500 + earnings from my deductible IRA and use it to contribute to my Roth IRA for 2018 – if possible.

I’ll use the $6,500 for a 2018 Roth IRA contribution and the earning towards my 2019 Roth IRA contribution – if possible.

I recognize I need to get this done in a hurry. Today is 10/8/19 and I need to get this done by 10/15/19.

I’m just checking to make sure that it is OK for me to do this or am I not allowed to make the 2018 Roth IRA contribution at this late date?

Am I forced to withdraw the $6,500 from the deductible IRA and use it for a 2019 Roth IRA contribution?

Maybe I should just ask, “So what do I do now?”