I feel terrible...

I feel so bad as a mommy I know you cant protect your children from everything but I could have prevented this... I laid him on the couch and he fell off and hit his head. Drs say hes doing just fine and everything looks normal but I just feel horrible... I'm glad hes fine but this overwhelming guilt I have is just unbearable... As a mother I feel as if I'm failing at this whole thing... thankfully we are back home now and he is okay. This has been a really rough week... 1st sick with bronchitis now this my heart just aches...