Can a herniated disc be corrected on its own? Will it go away or is this a permanent condition?

Yes. Yes. Herniated discs do heal. Surgery is not a requirement unless you have very specific and obvious complications. Back pain on the other hand may or may not be related to the disc or to its recovery. Disc does not equal pain and pain also does not equal disc.
Yes/No. Surgery will remove the disc so it will not heal normally but can result in reduction in pain and resolving any lasting nerve damage due to the disc herniation. Healing on its own will take time and may keep the integrity of the disc intact which may be the best at keeping the disc as normal as possible. Healing on its own can take up to 6-9 months or longer.
Yes almost. Sympoms (leg pain )abate in many over time , subsequent imaging shows the disc herniation shrinking but it dosent go back in where it came from and return exactly to pre injury status.