Help!! shaken baby syndrome.

I feel like an awful mom and I have such bad anxiety right now. I was holding my baby in my arms. He was laying down with his neck supported by my forearm. I had to give him a bottle and instead of using the opposite hand to shake the bottle of formula, I shook it with the hand that I was holding/supporting his head with. Now I’m terrified to give him shaken baby syndrome. He seems OK, but I’m so scared. I feel like such an awful parent, I don’t know how I did that. It was only for a little bit but still I’m so scared. He didn’t cry or anything like that he seems OK I just wanted to get some opinions.

**** thanks evryone i think hes ok, i am just a FTM with postnatal anxiety. I appreciate everyones imput!