HI, i have the same problem, i've been trying to fix it for weeks. it occurred under different circumstances than yours though.
i thought it may be linked to a bad uefi firmware since it is a known issue and ms relased a fix for it. but i can't isntall their fix.
i am able to get into windows sometimes, i've tried all the same things you have so many times.
i'm going to a ms store today to see if they can do anything.
ill let you know if i make any progress
