Should I negotiate my severance? - 20 weeks in

The company sent a severance agreement with a release of claims, and I am unsure what to do. It has been weighing on me all week. There is a non-disparagement clause. Did anyone negotiate and succeed?

Read the release carefully. Mine included things I did not expect, like a non-compete.

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