Aw Jeff I'm so sorry. There will be other jobs. And the guy sounds like a butt head so maybe its a bullet dodged.
The back thing sucks big time. A walker? Yikes. Watch out for those pain meds my dear! I have back and hip problem and it sucks a bag of you know whats. You have my sympathies.
Its hard but this too shall pass. A big part of staying sober for me is knowing that sometimes I just feel like poop. And there really is no way around it other than through it. And when I'm physically hurting, as well as mental, that just compounds things.
Hang in there. I can assure you that drinking or using will not help one little bit. That whole thought process is a lie.