Yikes! Thank goodness your boss was proactive and contacted your SIL to check on you. It's good she arrived promptly and called 911. It also sounds like you had really good caregivers to pull you through, too.
Sorry about your toe, but it sounds like the docs did a good job in saving your foot, with such impaired blood flow. Gangrene can be very destructive, fast.
Sounds like you had an Angel with you. Glad you're feeling better. Hope you continue with improved health, with no further complications. Best to you.