Hard unmovable lump on side of my right knee

Hi guys, 

               New here just looking for some advice please as my health anxiety is through the roof. Long story short about 6 years ago my partner was up in the loft when an extremely heavy speaker fell and hit me on my knee. I had to put my knee out because my toddler at the time was trying to come up stairs. I did go to the drs, the dr said all was fine. Last November I had another accident on the same knee, my right knee. It sounds stupid but I climbed on to my dressing table to shut my bedroom window. I was wearing tights and fell into my mirror. Was in agony got quite a few scars of leg to show. At the time my knee did swell. With it being a busy time of year and having children I just got on with everything and didn't think anything of it. In January I first discovered the lump but again didn't think too much of it. Now with the weather being nice I've had my legs out and I'm just obviously noticing it constantly and I'm absolutely petrified. It's hard unmovable painful it's about the size of a marble, it's not grown and it doesn't feel hot to touch. My bestie is a nurse, a sister actually and I finally asked her opinion last weekend when we were out for bottomless brunch she just said I need to see a dr asap and of course was trying to reassure me and said many medical things but of course dr googles my go to and I'm just so bloody scared. I'm having. Sleepless nights every night. I'm so frightened that I have bone cancer. I have a drs appointment on the second of June. Please if anyone has any advice I would greatly appreciated it.