Man this sounds an awful lot like what I've experienced from a vagal nerve problem. Any kind of drugs can affect it. Any kind of poisons coming out. I did the order of cleansing: colon, liver, blood, lymph and tissues. That took me 6 years, but the vagal nerve ended up being affected. I suspect it is toxins coming out still from drugs or it's the CNS healing, but it sounds exactly like what I've suffered for a long time now. Do you remember a time of being severely poisoned? If I were you, I would try the cleaning out procedures, then do evening primrose oil. wheat germ oil and other good omega 3 oils and see if it makes a difference. The vagal nerve and it's branches run all the organs, so constipation can definitely be a problem. Do Schulze's #1 formula and make sure you eliminate stuff in your bowels every day. Every one of your symptoms sounds like this nerve giving you a problem. I've let you in on what I'm doing.
The chiropractor might have done something that affected the fascia that got your posture back in line, plus you've had a baby and your nerve could be affected just from the difference in how you stand after having the baby.