Your story has been accepted. Cool. If it was published next week that would be great, but it's slower than beans out there which leaves plenty of time to ruminate. Someone is actually going to read what I write, weird. Who is going to read it, anybody? The worst part about this stage is rereading your story. I did this once, made revisions, sent it to the editor, and asked if he could print this much improved version. But of course I couldn't stop. I sent two more rewrites, promising the last was the last. My roommate told me to leave the poor guy alone, and I finally did. Once your story is out in the universe, let it go.
You've received your contributor copies. As you skim through your story you see typos. Gasp! Or the table of contents reads your story is on page 21, but it's really on page 22. Oh no! Or the editorial states your story was submitted as creative non-fiction, but it wasn't. Ugh! Or, my favourite: your last sent version (The National Corvette Museum is in Bowling Green, Kentucky NOT Bowling Green, Ohio) didn't make it to the printers. I did cry about that one. Do not dwell. Take heart that someone wants to publish your work and get back to the task at hand - writing.
You're writing a new story. You wonder if you will ever be published again? I don't know if this ever stops. Occasionally, you pick one of your publications off the shelf to remind yourself that someone gets your writing. But this has trappings of the first stage because your writing has improved, right? You will see lines and think, god that was crap; or realize, wow all of my characters are named after dead pets. Stay focused on the craft and the writing you are doing now. This 3-stage cycle will repeat, I promise.