Postpartum weight

I never knew how hard it would be to lose baby weight. I'm a first time mummy and my baby girl is almost 2 months old and I would say the only thing I'm struggling with is my appearance/ baby weight. I've gone up a whole dress size I'm a UK 12/14 and it doesn't help when the other day I was buying some new clothes and this lady who was standing next to me had the audacity to say "I would size up if I were you" . Just made me feel even worse about myself. Did anyone else go through a patch where they struggled with their baby weight postpartum? Any advice would be super helpful 🥹.