I recently sold a story for "real" money for the first time in my life. Yay! I got the email at 11pm and said "Oh, my god" loudly enough and with enough force that my partner ran out of the bathroom to make sure I hadn't stabbed myself. But as soon as the legitimate shock faded I started thinking about a.) what on earth they must have been thinking, and b.) how on earth I would get to the next milestone on the professional writer trail.
This is a weird double consciousness right here: on the one hand you think you cannot possibly be worthy, that whatever you've submitted is honestly not ready and someone clearly had an off day on the editorial side. On the other hand your eyes are so much larger than your stomach and you can't stop thinking about the bigger markets, the anthologies, the book deals. Presumably after that it's the series contract, the foreign rights, Hollywood or The CW.
I don't even want to continue this post because I know how many of these I've read from other authors I love who all say the exact same thing, yet every time I read another one of those it's comforting the same way a hot chocolate when you can't sleep is comforting. You know it won't really help you in the long run, and it's probably all psychosomatic anyway, and yet.
Obviously we all suffer from impostor syndrome now and then, and anyone who doesn't is likely a horrible person not worth your time. I just hope that I'll get better at talking myself out of feeling like I don't belong in the room, on the table, on the page.