I did it!!!! I sent the email AND I FEEL AMAZING. I couldn't figure out how to explain that I sent this way past when I should have, so I just opened the email with this:

Hi,

Thank you for your patience over the past few months, I was unable to finish writing a reply due to force majeure.

sentence about what the email is about

With this new request there is ample documentation, coherent and eloquent arguments, all accompanied with supporting evidence that should imbue a greater sense of understanding regarding the request upon reading.

Regards, name

Attached with literally what I had wrote all those months ago (polished with an hour of proof reading + fixing up citations). It was this easy to do, but apparently it was easier to have panic attacks instead... I'm just so glad it's over, now I can finally read and action the "new" emails I have pilled up over the past couple of months!