Help Luigi Beat Pneumonia

My name is Shannon. My fiance, Brandon and I are both working college students. I'm in my final semester of graduate school and and Brandon is finishing his undergraduate degree in night classes while working full time as a paraprofessional with mentally-disabled children. We have a 2.5 year old dachshund mix, Luigi, who was recently diagnosed with a condition called Mega-Esophagus. This condition  causes the esophagus to enlarge and the muscles don't work properly so food and water do not want to stay down. We joined several facebook groups right away to learn more about the condition and the best ways to manage it. We have been feeding him only soft food and holding him in an upright position to help with keeping things down, along with giving him anti-acid meds. 
A risk associated with Mega-E is Aspiration Pneumonia because dogs will regurgitate the food and water that doesnt properly travel down the esophagus and some of that liquid can get into the lungs. Two weeks ago Luigi was diagnosed with pneumonia after we discovered him lethargic in his bed. He was given one round of two antibiotics and x-rays from five days ago showed the pneumonia was mostly resolved. 
On Tuesday, January 27, I noticed Luigi was having some trouble in the morning with his food and medicines, so I held him upright for longer than normal. I went to run errands and when I came back, he had regurgitated 4 times, he was shaking, and breathing rapidly. I picked him up to comfort him but he would not calm down. It was clear he was struggling to breathe. 

I took him to the vet and they immediately put him on oxygen. They kept him overnight on IV fluids. The report this morning is that he is not doing better. When taken off oxygen, his breathing speeds up. He cant even keep saliva down so there is a concern that his esophagus is not functioning properly at all right now. The vet recommends that he be transferred to the U for more critical care. 
We have already spent over $1,000 in the last month on medicines and vet visits. I am not the type of pet owner to put down my baby just because he is sick and caring for him is getting expensive. That is why we need help. The additional care could cost $2-3,000 to get him through the pneumonia so that we can focus on the Mega-E. This pnemonia is life-threatening but the Mega-E is a manageable condition. 
Please help if you can so we can get Luigi back to doing the things he loves - chasing the cat, snuggling his favorite Ducky toy, peeing on trees, and barking at animals on TV. 
Thank you.