My Name Is Mary. I Have Stage4 Breast Cancer And

My name is Mary. I have stage4 breast cancer and have been on xgeva q6weeks. About a year ago I had a molar removed but a chip of tooth was left in. I thought it was all healed but then I started having problems. The chip has gotten much bigger and it has moved leaving a big gaping wound. when ever I strain in any way (blowing my nose) it starts bleeding profusely. What should I do