Sudden back pain

Hello,

I thought I could maybe get some advice here. I'll give as much information as I can and answer your questions.

I can recall in the past 3-4 months of a sore back but haven't thought much about it. A few days ago I had an episode of severe low back pain in exercise class. I somehow managed to make it back home. It hasn't resided since and I haven't been able to really get out of bed. I've also had trouble sleeping as a result.

My pain in the lower back is achey, and I feel it along the back of my left leg a very sharp pain. Past my knee's and towards my foot I can feel pins and needles. The pain and sensations haven't gone away. I went to the doctor and said its inflammation in my lower back but isn't sure what is causing it, might suspect it is a disc hernia. He's prescribed me pain killers for the moment. Should I be concerned? I'd like to get down to the bottom of this. Is there anything I can do at the moment?

Thanks