Negotiating an offer, is it too late? - 9 months and counting

I want to negotiate but I am afraid they will withdraw. I have been trying to stay organised about it. I have a competing interview next week. What wording worked?

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.

Most employers expect a short conversation. Mine did not even blink.