Severance agreement arrived, need a second opinion after 12 years as an accounts payable clerk

The company sent a severance agreement with a release of claims, and I am unsure what to do. I do not usually post, so bear with me. There is a non-disparagement clause. Did anyone negotiate and succeed?

Thanks for writing this out. I went through something close to it 2 months ago, and it settled down once I kept a simple log of every call and form.