Lump on lower leg

hi everyone! 

Just posting here as I am worrying so much although I know it will prob be nothing I need some advice!

about 7 weeks ago I started having really bad back pain to ten point I was stuck on the floor for w few hours. The pain spreads to my hip and it’s still no better now. Awaiting physio but not till the end of September. (I briefly spoke to physio on the phone who said it sounds like maybe a slipped disc) I’ve also been getting a very achy leg and then I saw and felt a hard non moveable lump, almost like it’s part of the bone itself on my lower leg to the side (few inches above the ankle) I’ve booked in to the dr but cannot be seen till the 13th sep. 

I’m really afraid it’s something sinister. The pain in my back and hip is so painful and this lump is very achy. 

Anyone had anything like this before? 

Thanks in advance