I don't know the yoga excercises that you did, but if you do the excercises on all 4's, you need to stop them as they will make the pain increasingly worse. My yoga teacher told me that with my back problem, that I should only do things where I am on my back.
It is my opinion that the pain should not be getting worse, before it gets better. Your body is in pain, as a way of telling you that something is wrong. Was the Dr. you saw a spine specialist? That is who you really need to see and they will do various tests to dx. you. If you want to know what is wrong, you can have an MRI and EMG/nerve conduct done or even a discogram. These are some of the ways to find out for sure what is causing the pain.
Please don't make things worse by doing anything that worsens your pain, until you know what it is that needs to be treated.