Severance and unemployment, do they overlap? (update)

I was offered severance of 15 weeks after being let go as a pharmacy technician and I am unsure how it affects benefits. I have a mortgage and need to plan. How did your state treat it?

Thanks for writing this out. I went through something close to it 10 months ago, and it got easier once I kept a simple log of every call and form.

Some states only count certain kinds of severance. A local workforce centre could tell me which.