The rate at which nerves grow back is 1 inch per month.
So nerves that grow back are slow growing and do not grow back very fast.
But if the nerves are gonna grow back the nerve will grow back at 1 inch per month.
In 12 months the nerve should grow back to 12 inches or 1 foot.
During the nerve regeneration and nerve growth it can be painful so you can experience pain while the nerves are growing back which is normal.
After the nerves grow back fully then you should not experience much if any pain at all.