You are NOT a drama queen. That is your baby and I just know you are feeling so worried about scared now, understandably.
I remember when I took Jackson to the vet for a GI upset, I was not prepared at ALL for them to tell me he had to stay there overnight. I immediately welled up and waited until the doctor left the room to just cry and say goodbye to Jackson. I had left him overnight before but only at my fathers house, never anywhere else. He's super super attached to me, as I am sure Callie is to you, and I just felt like an awful pet parent.
Just know that you are helping her and she will feel like a brand new dog in a few weeks when she is out of pain!
Good luck with everything. Keep yourself calm, I know it's going to be hard, but it will be worth it to have her in your arms again tomorrow.