Should I negotiate my severance? after 9 years as a recruiter

I was offered 9 weeks of severance after 9 years as a recruiter, and I have a few days to sign. There are 9 people counting on me, so I am trying to be careful. There is a non-disparagement clause. Did anyone negotiate and succeed?

Keep everything in writing and save the confirmation numbers. It made the follow-up calls so much easier.

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