Tumor in ulna- A tad worried

I am 64 and I just finished up with Radiation for prostate cancer in May. My gleason score suggested that it was just in the prostate so Drs werent worried about mets.. Well I was having hip pain and was told to see a ortho.. He did xray on my hip saw athritis so he ordered a bone scan.. He was talking hip replacement.. During the bone scan my left Ulner lit up.. They did a xray and a MRI and there is a tumor in my bone marrow..  This was back in August.. Sent to a Ortho Oncolgist... He wanted to do a Biopsy. But I was told by the previos ortho that a biopsy may affect the use ofmy left hand because it was so close to nerve bundles.. I play the upright bass professionally.. So speaking with the Ortho Onclogist we determined to wait for 10 weeks, do a x ray and see if it has grown..  This could be benign.. Or I could be in denile..  So I have appointment first week of October..  It hurt a little on the scale of 1- 10 about a 2 or 3. I know the pain is there..  But it doesn't stop me from doing anything..  But the stress of not knowing what it is is really high.. They did test for multiple myloma. The first test came back some what positive.. Then they did another test and came back negative.. Reading what they would have to do if it is bone cancer scares the bejebers out of me.. All sorts of thoughts running through my head including learning how to play a diffrent instrument that can be managed with one hand..