Severance offer, what should I ask for?, customer-service rep here

I was offered 7 weeks of severance after 7 years as a customer-service rep, and I have a few days to sign. There are 7 people counting on me, so I am trying to be careful. 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.