How can you deal with the back pain caused from an epidural?

If it is pain. At the insertion site, warm compresses and anti-inflammatories should help. If it is more severe you should speak with your anesthesiologist who may refer you for an MRI and neurology consultation.
Hard to say. See a spine specialist to make sure nothing was damaged or irritated after the injection. If it was for labor epidural if you are not better in a few weeks, would definitely consider repeat MRI to see what is going on.
Refer to answer. There are three causes.Epidural bleeding, leak, and catheter break up. To find the actual cause refer to your physician.