Someone help with my leg pain! ?

I am a runner, and I have been running the same running regimen for the past 2 years with no problems. Recently, my lower legs have been bothering me at night, so I took 2 days off from running and decided to do light biking instead. The pain is getting worse (feels achey, weak and pinchy) and is widespread on my lower leg and even radiates to my knee and ankle. My lower back is also bothering me which makes me think it might be a nerve issue? I do not think this is shin splints because the back of my legs hurt as well. I have been very tired lately also. Any ideas of what this might be?!