Puppy Illness

We got Emmie on June 15th, she was 2 months old. A couple weeks ago she started to get very sick, not able to walk, and a very high fever. We took her to the vet multiple times, thinking it might be lyme disease, manengitus, or parvo. The tests all came back negative, and her blood tests came back normal. We can't figure out what is wrong with her. Her fever was at 107 yesterday which was the highest she has ever been at.

Has any other owner experienced this with their goldendoodle before? Could it be a breeder problem? The vet told us that this is the last resort, the last time we brought her in, and that if she does not get better within 2 weeks we will have to think of putting her down. She is only 5 months old, we shouldn't have to be going through this with our puppy, not yet! we are just heart broken. Anything will help at this point, if you have gone through this with your dog please please let me know.