My mom thinks I’m an incompetent mother

Today I was changing my babies nappy and forgot to put a mat underneath him. Obviously the one time I don’t put a mat under, he poos all over the carpet. My mom was there and I looked at her blankly and she said “what happened?” I said “he just pooed on the carpet”. She obviously got annoyed, and processed to say “you shouldn’t have brought a child into the world you can’t even handle him”. This really bothered me and I began to cry as I was changing him. She saw I was crying and just made me feel worse, saying “why are you crying wow” condescendingly. I went to my room to feed him and she came in and hugged me and gave a half arse apology, saying she’s sorry but she’s my mom and moms sometimes say these things. She said if you lived with your in laws you would have copped it worse than what she said to me. It was the most meaningless apology and she thought it was dramatic of me to cry at her comment. I’m obviously now doubting my capability of being a mother. I hate that being a mom means you can just throw words around and not expect your kids to get hurt.