Severance agreement arrived, need a second opinion after 11 years as a barista

I was offered 11 weeks of severance after 11 years as a barista, and I have a few days to sign. There are 11 people counting on me, so I am trying to be careful. There is a non-disparagement clause. Did anyone negotiate and succeed?

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