Very similar situation - to THE T - happened to my last year.
I was ready and mentally prepared to quit. I have planned my sabbatical and took it, not in the summer time, but in April. Plan was to give 2-4 weeks notice and sail in June into summer. Instead I was lay-off first day after I came back from sabbatical. And I did receive a VERY generous severance package (almost ONE YEAR!).
However, I had a bit of a resentment, because I did not leave one *my* terms, even though I have received MORE money then expected.
A year later I'm thinking I was *stupid*. Emotions>>logic. Also had the anxiety about money. And come to realize it is just money :-). But i have still not found my groove/purpose. Focus on that, it will bring I think more closure then a bucket of money.