If you had internal fixation (plates, screws) I doubt an accidental, short duration, weight placement would cause harm. Pain tells you to stop doing something so that you don’t cause injury. I would certainly let my doctor know, though, especially if I had new swelling or other symptoms.
Use the walker if you are more comfortable. Crutches are more versatile but you have to be confident for your own piece of mind. I use the walker for short distance or for extra steadiness for getting in and out of the shower. Hopping with the walker has started to cause my hands to hurt. Heck, I use my wheelchair when I need to go a distance or want to go faster. Don’t worry about any stigma- this is about your physical and mental health.
As far as your muscles not responding, expect your therapist to introduce some electrical stimulation to get them to “wake up.”