Severance offer, what should I ask for?

I was offered 17 weeks of severance after 17 years as a data-entry clerk, and I have a few days to sign. It has been weighing on me all week. I do not want to leave money on the table. What did you ask for?

Thanks for writing this out. I went through something close to it 9 months ago, and it got easier once I kept a simple log of every call and form.