Postpartum weight gain

I’m 4 months PP and literally no matter how clean I eat and how many times a week I walk I’m still gaining weight and it’s killing me. When I got home from the hospital I weighed less than I started my pregnancy at and have since gained 13lbs and I have no idea what is going on. I’ve been eating clean (with the weekend exception here and there) walking with the stroller 5 days a week.. I’m exhausted, and so overwhelmed I can’t even look at myself in the mirror i don’t know what is going on.

Did anyone else go through this?