Same problem here, buy I'm quite sure my issue was self inflicted, as I believe I shorted 5.0 VDC Power with 3.3 VDC power.
I read all the points in the Boot Problems Sticky, but since my multi-meter fails to get any reading from the 3.3 VDC pin after my boo-boo, I'm pretty sure I killed it.
I have a number of hours invested in setting up my OS and environment. What's the likelihood of ordering another Pi 3B+, swapping out my previously working MicroSD card, and return to a working environment? I guess my question is whether I could have also fried the SD card.
Thanks in advance!