I HAVE A MININGNOMA AND GOT TRIGEMINAL NEURLGIA WHICH ALERTED

I HAVE A MININGNOMA AND GOT TRIGEMINAL NEURLGIA WHICH ALERTED THEM TO THE FACT MY TUMOUR HAD GROWN AGAIN AFTER 18 YEARS.. THEY COULD NOT OPERATE ON THE TUMOUR IN THE SAME PLACE AGAIN SO THEY GAVE ME 6 WEEKS OF RADIATION TREATMENT TO THE BACK OF MY HEAD. NOW THREE MONTHS LATER I STILL FEEL SO SICK. WHAT EVER I DO I CAN NOT GET RID OF THE NAUSEA. I AM TAKING ONDANSETRON 8MG. CAN I DO SOMETHING TO STOP THIS HORRIBLE NAUSEA. ONDANSETRON GUMS YOU UP AS WELL.