Do I worry about short story submissions?

The answer: Usually not.

There are some exceptions. When there is a story of mine I really like, and I've submitted it to a publication I really like, then yeah, I ponder it a bit. Yes, I'd like to see my story in that publication.

But if my story isn't accepted, I don't fret over it.

Why?

Because I usually already have another market in mind. Sometimes it's even a better market, meaning a market I'm really more interested in. Then you might ask: Well, why didn't you submit it to your so-called better market in the first place? There are lots of reasons. Sometimes it's just because a particular market isn't taking submissions at a certain time, or their reading period is over for the timebeing. Also, sometimes I'm not sure if a story is right for a certain market, but I think it would work fine for a different market. It all gets floated around a bit.

Sometimes I hold off sending a story to a publication because I already have something submitted to them. Even if they don't have a rule against more than one submission from a given writer at a given time, I've never submitted more than one story at a time to a publication. I'm just funny about that. If an editor specifically asked me to send them several stories, then I would. But otherwise, nope.

I think one of the keys to keeping your sanity as a writer is to not worry too much about your submissions once they've been submitted. Just keep another market in mind in case the story doesn't go over with the editor.

Otherwise, you could worry yourself nervous about every story you send it. And that's not good. If nothing else, it hurts your health. And worse, it could negatively affect your writing that next story.