I feel like the WORST mom in the world =(.....?

Oh hun you are not the worst mom in the world...I am lol...I did something similar yesterday to Sarah. We were on the couch playing I had her on my lap facing me tickling her, and she went back and her head went between my knees and she smacked the back of her head on the base of the couch, which is really hard. And she didn't cry at first, I think she was stunned, and then she screamed like crazy....then I started to cry...she didn't want to look at me for a good 5 mins..she let me hold her and cuddle her, but looked away every time I tried to look at her....Broke my heart. So a few mins after the tears dried, and I made sure she was going to be ok, no bump just her feel bads were hurt..she was back to the norm and hugging and kissing me again. I felt like ca ca . But that's about the 2nd time mommy bumped her lil head :(