Severance offer, what should I ask for? - any advice?

I was offered 10 weeks of severance after 10 years as an IT help-desk technician, and I have a few days to sign. I do not usually post, so bear with me. There is a non-disparagement clause. Should I see a lawyer?

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

An hour with an employment lawyer cost me a small fee and made me feel much safer about signing.