Should I negotiate my severance? - any advice?

I was offered 17 weeks of severance after 17 years as a software tester, and I have a few days to sign. I have read a lot of threads here and could not find my exact situation. There is a non-disparagement clause. Should I see a lawyer?

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

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