Hey mate, I was in the same situation a while ago. It was the fact I tried to hide my stutter from her that made it worse . As soon as I was open with it to her, it was as if a huge weight was lifted, and my confidence rose again. It was like a domino effect because once I got confident again my stutter even though it was still there, was nowhere near as bad. Just try and embrace it and accept its part of you.