My Mac is bricked

Corrected: Do you have access to another Mac system which you can create a bootable OS installer that is the correct one for your system?

You'll need to go here to get the OS installer: How to get old versions of macOS

You need to stick with OS-X El Capitan (10.11.x)

First format your 32GB thumb drive with GUID Journaled file system using the Disk Utility on your working Mac you're going to use for the OS installer

Follow this guide to create the needed OS installer How to make a bootable OS X 10.11 El Capitan installer drive

You should be able to fix your system!