Should I negotiate my severance? (update)

My manager said the package is final, but the letter gives me time to review. Thank you in advance. I do not want to leave money on the table.

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.

I asked for two more weeks and a neutral reference. They agreed to the reference and added a week.