Hi Flower - I imagine caring for a newborn is very difficult with chronic pain in the mix - it's hard for all new parents.
Have you ever tried the muscle relaxant Baclofen? It works differently from the other muscle relaxants, so it might be an option. It is supposed to be less sedating too.
Do you have one of those foam rollers from your PT? Mine gave me this exercise that REALLY helps using the foam roller. I couldn't find exactly the exercises, but it's similar to the one in Figure 2 here:
www.physioadvisor.com.au/11088750/foam-roller-exercises-foam-rollers-physioadvis.htmThese are just two small suggestions, because it sounds like you are doing everything possible to help your pain. Childbirth and having a newborn are both tremendous physical and emotional stresses, even if it's good stress. Enjoy your little boy as much as possible while you are patient with your body as it recovers from those stresses. Gentle hugs to you, and congratulations on your little boy!