I am having very bad back pain and now my foot is going numb should I go to the ER

Yes, that's the kind of trouble is was having. It was a disc bulging into my spinal cord causing the numbing. Go to your general doctor, so he/she can order x-rays and a MRI. Trust me, it'll get worse with time if you don't do something about it.

Most ER's won't do mri. You would need to go to an orthopedic. Sound like bulging disk pinching the nerve that runs to your foot.