Exercise Help Needed <details>

I know I need to start exercising, however I have severe lower back pain that with many exercise movements turns my upper legs into balls of muscle spasms. I had the nerves burned a year ago (which is probably the cause) but now I'm stuck. Bending is terrible, instant pain, however walking helps only if I am not in pain. Stairs also cause terrible pain. I need to find a way to exercise and unfortunately, I can't afford a gym with a pool, because ultimately that's probably what I need. Anyone have any advice? On a side note, I live in Ohio, and we have over a foot of snow, so walking outside is not really an option either.