Hi My Dad Has Felt Weak Then We Did All

Hi

My dad has felt weak then we did all tests,they showed nothing except he had scaring in lungs from pneumonia and higher white blood cells count . He still felt weak,really ate a little(he was really big eventhough he had diabetes for several years) and he had urge to vomit. Doctors gave him antibiotics since they believed hos gall stones moved. We did all tests again and they showed enlarged retroperitoneal lymphnodes and again white blood cells high. Now he has been having fever for some time and he had bacterias in his mouth (candidiasis) which we cleaned and his mouth started looking better and still he has urge to vomit,he doesn't eat,only water,juice,tea. Oh and he had some little stones and sand peed-out. Doctors told him he could only do biopsy but we are against biopsy so we really don't know what to do more.please help!!! Any advice?