Negotiating an offer, is it too late? after 14 years as a sales associate

I want to negotiate but I am afraid they will withdraw. This is my first time dealing with any of this. The benefits are decent. Did it backfire?

Thanks for writing this out. I went through something close to it 10 months ago, and it got easier once I kept a simple log of every call and form.

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