It is not abnormal for me to have back pain in my lower back. I tend to sleep really bad, tossing around at night so I may have back pains at least once or twice a week. I did a little research on the S2 & S3 since you mentioned it. I did see a few other extremes that come along with it. Gladly I am only expereincing the pain in the groin.
- Loss of control of your bladder or bowel.
- Breathing difficulty.
- Pain in the lower back.
- Pain extending down the back of your legs.
- Spasms of your muscles.
- Loss of ability to feel heat or cold.
- Pain in the groin and buttocks area

I will definitely keep this in mind if I end up speaking with a neurologist. I do feel like 99% of my problems will be weight related. I would like to lose weight and see if this solves my problem, I know that is easier said than done. I am 5'10 300 lbs and would like to lose about 75 pounds. Before this issue I was excercising 5 times a week daily and since it started, I stopped entirely. It is hard to excercise especially with the issue I am having. I hope to find somekind of middle ground so I can continue to work out. Seems excercise is the solution to a lot of things in my life.