Have you tried writing what you feel?
It can be a good starting point.
If u can't read it to her, she might read it herself.
Depends ...
But worth a try...
You could start with "I'm thinking of leaving because I just don't seem to be getting anywhere..." and if she's responding in a way that makes u comfortable but you still can't talk, tell u have notes...
I'm a shocking talker!!!

Take care

FT