This is also my second baby and my back is tore up!! My Dr ended up sending me to physical therapy and let me tell you its working wonders!! I never felt this pain with my fist baby at all!! She does manual therapy on my back and is teaching me eccersises to help maybe you can ask your Dr about it I don't know what do without it!
I feel the same thing a really sharp pain in my lower left side.
I have used a heating pad on low/medium heat. Only on my back and a little on my sides never directly on my belly. It helps a lot. If it feels to hot lower the temp and take a break from it.
Ima ask my doc lol . I really can't take it sometimes.