I totally understand freaking out when anything is wrong. Glad to hear it is not a big cut. The bandage probably does feel weird and that is likely what she is after, trying to scratch.
I understand now what you mean about the collar, getting her leg up into it. I'm very sorry that I don't have any suggestions.
The only thing I can think of is to try to distract her, hold her on your lap and massage her to calm her down and encourage her to sleep.
Hoping someone else will think of something clever.
Keep us updated on her recovery.