I too have a similar problem on the right side due to pronation of my right foot. The rib pain went a way for a while but is back again. As Jaybay mentioned physical therapy is probably advisable but I would also consider other therapies such as trigger point release therapy which can speed up the process of recovery. Somatics may also be a useful thing to learn as well as Pilates. Both of these are kind of essential for long term well being.
Physical therapy may be able to help you learn how to move in a way that won't aggravate the rest of your body. When one body part is compromised, we compensate for it and can injure another part in that process. Careful attention to maintaining a neutral spine posture at all times would be a good place to start. A physical therapist can show you where that neutral spine posture is and help you learn how it feels so you don't have to check in a mirror or have someone else check you. There are also exercises that will help strengthen and stabilize your trunk while having to compensate for the limp. In a way, it's like learning how to sit, stand and walk all over again. Like any other therapy, it will take some time, but if you really apply yourself, you may be pleasantly surprised at the results. Good luck!