Severance agreement arrived, need a second opinion (update)

I was offered 16 weeks of severance after 16 years as an insurance claims processor, and I have a few days to sign. I worked as an insurance claims processor before this. There is a non-disparagement clause. Did anyone negotiate and succeed?

Ask for the offer in writing and do not sign on the spot. A day or two to think is normal.

An hour with an employment lawyer cost me a small fee and made me feel much safer about signing.