Nevermind, I was able to get it into bootloader via: 1. Plug phone into computer.
2. Hold power + both volume.
3. As soon as charge LED turns off, release volume up.
Once I was in bootloader, I loaded recovery and was able to restore from backup.
It looks like I am running into the exact same problem you were having.
How did you manage to get the phone into the bootloader (that white screen you showed a screenshot of)?
Thanks!