I have had back problems all my life, so I know how annoying it can be. I have been going to Dr. Andrew Dossett at the Carrell Clinic on Central Expwy near NorthPark. I have been very pleased with him, but do not know if he is on CIGNA, I have United Healthcare. I noticed many people recommending Chiropractors, but I have not had any experience with that and frankly, they scare me a little. I have heard people say they have gone to a Chiropractor and it helped, but they have to keep going on a regular basis, like once a week.
If I were you and you have a family doctor or gynocologist that you like and trust, I would talk to them first and have them send you to someone. No respectable doctor is going to recommend surgery right off the bat. They need to do an MRI to see what is going on and will most likely recommend physical therapy. I have had wonderful results with physical therapy and you need to do regular exercises to strenthen your core muscles to support your back.
You should not be taking a prescription pain medicine over a long period of time, but you may need to take an anti-inflammatory (like Advil or Aleve) for several weeks to decrease the inflammation. The next step after physical therapy and anti-inflammatory, would be an injection of cortisone. I had a herniated disc and was unable to relieve it with the other treatments. It was causing pain and numbness down my left leg. The cortisone shot was amazing and relieved it immediately.
I would also recommend that you try ice packs on your back. I always used a heating pad to give me some relief, but my physical therapists put an ice pack on my back and it really helped. Just buy a couple of bags of frozen peas and keep them in the freezer to use every night. I agree with the person that said you need to be careful how you lift. Always try to life with your legs and not your back. If you are carrying your child slung on your hip, then that is probably not helping either. I know it will be hard, but try to avoid carrying him as much as possible. I have known moms that got carpel tunnel from lugging a huge baby around. At 17 months he should be walking pretty well and not need to be carried as much. Use a stroller and encourage him to crawl up into your lap, stroller or car seat on his own, rather than you lifting him.
Hope that helps some and hopefully you can get some relief soon.