Big-- You said more in that paragraph that in hundreds of random posts I've read.
One-- We know. You are not alone in this. We have felt as you are feeling, some more recently than others. It does get better, and you will surprise yourself with the strength that you are about to find.
Consider a L to check over all the paperwork before signing anything. You are still in shock and not likely to think of all considerations. Your employer might even have a discount or free consultation.