Help little Cachito walk again

Cachito was shaking and trembling not stop since last Friday. Not eating or drinking water. Hiding and not wanting anything to do with anyone. He wouldn't walk much and could not go up or downstairs. All this totally opposite of his normal vivacious, loving and big food begging behavior. After 3 different animal hospital saw him, today, it was finally discovered in another set of X rays that he has severe lumbar degeneration on his spine. This is common in Doxies, but very unusual at 5.5 years old. One of the docs said it is possible he suffered some injured when he was younger and got worse with the constant use of stairs(I love at a condo with many stairs). I just now recall when we rescued him, we were told his sister had been stepped on his back and her back was broken. I wonder if his initial owner also did that to our Cachito.

Reality is that, according to the Vet he won't get his spine back to normal, but the severe inflammation can be treated. Also, in order to continue quality of life he has to continue treatment. He also needs an MRI and ultrasound to determine other possible damage. So far I have maximized my tow credit  cards. I got all the meds needed to keep him comfortable buy can not afford the next part of the treatment.

If you know Cachito you will know how full of Life he is. One of the neighbors calls me "The Joy of the Neighborhood", but he is also "The Guardian", barking at new comers, but then warming up to them very fast. Everyone is also shocked at how incredibly sharing he is for a dog. Not minding our dog guests eating his food, playing wit his favorite toys or using his bed.
I have owned 9 dogs in my life and have cared for many of my friend's dogs and honestly never met a dog so sweet and smart...but of course I admit, I might be biased LOL.

Further more Cachito is the one who I believe brought hope to my younger son, when he was facing bad depression and PSD. Because he was a baby and a cute long hair Dachshund , we were number 11 on the waiting list. My son loves all animals like I do, but when he had seen Cachito's pic at Hopalong website his eyes lighted up like I had not seen in years, so i persisted and long story short, after the 1st 3 families on the list were not a good fit, Cachito come to us. He chose us. 
This loving and pure creature of God saved my son. It is our turn to save him.

We need $2500 to covered his other needed testing(next blood work, Pancreas assessment, MRI, ultrasound) next two months of treatment so he can walk with minimum pain again. Whatever help you can provide is hugely appreciate it from the bottom of my heart and I believe we are all deeply connected so I know Cachito is appreciating your support as well.