Help to get Kitty diagnosed

Hi everyone, my name is Raquel and my beautiful cat is Kitty. She has been vomiting for about a year now. At first, she was vomiting once a month approximately and the vet thought it was normal, maybe caused because she might have eaten a fly or another bug. However vomiting became something she was doing once a week and then once a day. Here the vet advise us to feed her just with dry food in very small amounts to treat a possible stomach inflammation. She seemed to get better but after a few weeks she was vomiting again. Then, we took her to another vet and he suspected ibd (inflammatory bowel disease), he gave kitty an antacid, a steroid injection and a change of food to treat a possible food allergy that might be causing the symptoms. Again she was better for a few weeks but started vomiting again. Here we had two options: A) assume it was ibd but more severe and just to treat her for that or B) run a couple of blood tests, ultrasound, and biopsy to diagnosed her properly either with ibd or lymphoma (cancer of the intestines). We wanted to go with option B and get a proper diagnosed but the blood tests cost us £600, and they were used to discard any issues with her liver, kidneys, and vitamin levels, but a mild inflammation of the pancreas was spotted. Now the vet wants to do the ultrasound to rule out any abnormalities that could point at cancer, however I am a PhD student researching on Alzheimer’s disease and for that reason we are not elegible for any type of benefit to help us pay for our baby nursery. All the money I get is used to pay the nursery and the money my husband makes is used to pay the rent, bills, food…but we are devastated not being able to give kitty the care she needs and deserves as she is out first baby, for that reason I want to ask for your help to get her properly diagnosed.