Congrats! I have to say I was skeptical, but very happy to hear you've pulled the plug.
Now, a quick preview of your next two weeks:
That Dir. who hasn't called? Get used to that. You are dead man walking now. Just chin up and do your thing, keep your head high. Some people get really odd when others leave, as you've probably seen, but it feels odder when it's you.
That work you know you have to get finished? Half of it, your boss might just swipe it from you - cancel you from meeting invites, etc. "But but no one else knows what to do!!!!" - yes they do, or they'll figure it out, or not, their decision. Let them take whatever they want. Don't fight it. Breathe deeply.
To those who you don't already count on as outside-office friends, prep a quick answer to "what are you going to do now?" that answers politely and closes off the question. Have something prepared like "Hah, that's what my wife wants to know, but we have some personal things planned." - the kind of thing that is will make 95% of people know they are just being nosy and won't push. And for the 5% that do, just something like "oh I won't bore you, hey gotta get this report done now!" etc.
Those that you do like and would like to keep in your personal network? Find time for lunch or coffee with them before you go. I remember those last several informal chats with people I respected and liked, and I'm really glad I found the time, the rest of those last weeks is a blur.
You will have some very uncomfortable moments as well as some really great ones, over these next two weeks. You will second guess yourself, but it will all be ok.