Punkin, I went through exactly the same thing just after my D was final. It felt like square one. In fact that part sort of intensified about a month after it was final. Then things started to change, slowly. I'm riding such a high now that it's hard to imagine that level of depression, though I do know it is just over that edge--I was at a party last night and got very gloom and doom in my own head on the way home, as I was, yet again, the only person there who wasn't married or in a relationship (and that counts a friend's mom in her 60's who is remarried recently). So it's on the periphery. But in general I see more happy and peaceful moments than sad ones, and you will too.
Like Holly says you are gathering strength.
I like how you said we were like a graduating class. It's uncanny how close a lot of our timelines are and I do think it has been a real source of collective strength.
M45 Bomb 6/09; EA 6/10; Divorced 1/11 Proud single mom of 7 little feline girls and one little feline boy "Fall down 53 times. Get up 54." -- Zen saying