TC, I was in the same position a year ago and I really feel your pain. It's a startling, jolting situation where everything goes upside down for a while. I ended up spending a week wallowing, not really wanting to talk to anyone, then accepting it and moving forward, perhaps too quickly, back into the job market. I found the hardest part was just coping with feeling irrelevant. I derived a lot of comfort from being in a niche industry and feeling very connected. What I found helped, was to act quickly, as people remember you best, and let clients, colleagues and competitors know that due to business changes you are ready to apply your skills elsewhere. Remember that they recruited you just a short while ago, you are still in demand, and the sting will lessen as you find a more fitting position anyway. I ultimately joined a client's firm I'd worked closely with, and incidentally always wondered what it would be like to work at, and have found it much more enjoyable, if less remunerative, to work with them. I did make the mistake initially of letting a friend talk me into helping with her startup for a bit the day after I was laid off. It ended up being a horrible idea.
So the advice may be, weigh your options carefully, but sustain current relationships vigorously in the first few weeks you're out. Also, I found negotiating the layoff terms futile and distracting. Sign and move on. Your efforts are best spent finding a new position that maximizes your happiness, and that will be worth well more than an extra month's pay minus legal bills.
Hope this helps.