your boss sounds like a real tool. Hope you can heal up in short order and get back to work soon. My back goes out every so often and I find these exercises will put me back in no time. Try this link:
https://orthoinfo.aaos.org/en/recove...g-program-pdf/
I think landscaping and brick/paver work is an art form! I hope you can land a job right out the gate. Hoping you can resist going to the drink. Be strong!