One of the things I’ve learned from “The Art of Learning” is that almost all kinds of negotiation will make you uncomfortable and thus you have to prepare for that kinds of uneasiness.
You need to know that they will try to take you by your worst fears, give you smaller timeframes, and so on.
And the takeaway from this is: take your time. Go slow, evaluate your options.
Any negotiation needs time, effort and dedication. Take yours, use it at your advantage.
Relax, take it easy and be sure that it’s worth it.