I've been having extreme back pain where I got my epidural during labor almost 2 years ago is this normal?

Lumbar strain. The point where the epidural is placed is same place where a lot of strain is placed during labor. Get evaluated because you may have another cause of pain.
No. Most likely its just coincidence that the same place you are having back pain is the place your epidural got placed for your baby. Typically l4/l5 is a place where most people have back pain at and one of the top areas for disc herniations in the back. I would consider getting an evaluation by your doc and maybe considering an MRI since you are still having pain 2 years later.