Worst mom in the world..

I dropped my nearly 2 month old son on accident about an hour ago.. He wouldn't fall asleep in his bassinet and loves falling asleep in my arms so I held him. I accidentally dozed off and he fell out of my arms off the side of my 2ft bed onto tile. He immediately cried, I jumped up and comforted him and he was okay after that. We checked his head for bruises and bumps, hes clear, no sign of discomfort. But we're keeping watch for 24 hours. My mom is watching him now and my boyfriend is trying to comfort me but I can't stop crying. I feel awful. I love my son more than anything and I'm supposed to protect him from getting hurt. I feel completely defeated..