6 wk pp and can barely walk

My dr told me after 2 weeks I could go for short walks. And I’ve done that around target or the mall. Well yesterday I took a mile walk with my 11 year old and my 6 week old. Well during my short walks my pelvic bone would hurt and I’d feel sore but after yesterday’s mile I am so sore I can’t walk up the stairs or even lift my leg into the car without sharp pain. And walking it feels like someone kicked me super hard in the pelvic bone. I’m not sure what’s happening but i don’t think this is okay or good. Anyone had any experience like this?