Diagnosing Sampson

This is our Sampson. He is the happiest, energetic dog you could imagine. He is our children's rock, and greatest adventuring buddy! Always tender to others, but alert for his babies.
At the beginning of June, Sampson had a mishap in the cab of our truck, and pinned his leg and hip and became stuck. He has always recovered from tumbles, but this was much more severe. 
He had trouble walking in the beginning,(shaky gait, hard to relive himself), but has quickly progressed to almost total paralysis of his back half. We have been advised that it may be a sever disk herniation and requires surgical correction.

We have had him seen by our family veterinarian on several occasions in the past few weeks, but there are direct answers.  We have been put in touch with a highly recommend Doctor that is happy to work with us financially, but we are stretched so thin with a newborn and moving.

We are asking for about half the expected costs for boarding, surgery, meds, and aftercare. 
Anything you can do to help us get our fur baby back to a happy pain free dog would be so much appreciated by our whole family.