Congratulations. Yes, it's a special moment.
Also a bit like having an old friend move away for while. You know they'll be back, but the habit of their everyday company, the casual 'drop in for a coffee if you're in the area' takes a while to wear off.
But that gap between finishing the first draft and starting to edit is important. You need time to disconnect from what is on the page and what is in your brain.
I would also recommend that when you do take it back out the drawer the first time you read it all the way through, taking a few general notes if you can't avoid the impulse. But without editing 'on the fly'. Try to read it as someone else would. See if it holds together as a story, make a note of any glaring gaps of discrepancies, but don't sweat the small details at this point. If the storyline pulls you along, despite knowing where it's going, then that's a good thing.
After that you can put your nitpicking editorial eyes in and get all OCD about it.
Writing and editing are two very different skills. The first is creative, building the structure or weaving the fabric. The second is refining it without losing the overall vision.
There's a lot to be said for taking up a non-writing activity for a while if you have another interest. Break out the tools and make something. Using your brain in a different way for a while helps to create that essential gap ;-)
Once again, congratulations.
Gyppo