Should I negotiate my severance? - what worked for you?

The company sent a severance agreement with a release of claims, and I am unsure what to do. I worked as a copywriter before this. There is a non-disparagement clause. Should I see a lawyer?

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.