Help with my 21 month old Poppy’s surgery

Hi my name is Sam. I have a 21month old coton noodle named Poppy. She is amazing but she has struggled for a while with weight gain, we decided to get the vets involved who referred her to a specialist. The specialist tried lots of different things and Poppy still won’t put weight on, the vet has now decided that she needs more investigation work as they believe she has a liver shunt, gastrointestinal syndrome and her teeth have grown wrongly so it’s affecting her gut as apparently it’s all linked, she also has issues with her mammory glands due to hormonal issues. We have insurance but it’s already half used and now we have been told it will be another £7000-£8000 to do the operations, CT and also removing the top teeth that are causing her issues with her eating. I am on disability and struggling to find this money and am asking for help which I don’t like doing but I have no other option. Poppy is a family dog all of us love her but she was primarily brought as a support dog for my daughter who has ASD/ADHD and this has gutted her aswell as all of us as we are just watching poppy lose more and more weight. Her ideal weight is at least 6kg and currently she is 3.3kg. We just want our girl better. Any help would be grateful.