Why does publishing my writing overwhelm me?

Here is what is actually happening. You have writing finished, or nearly finished, and instead of one decision you have made a pile: where to send it, how to format it, who to ask, what it means if no one wants it. You are trying to solve all of this at once, in your head, before you have moved a single hand. No wonder it feels heavy. It is heavy — you have built a mountain out of tasks that are each quite small. Notice also what you are doing with this overwhelm. It lets you avoid the one thing that actually exposes you: sending the work out and finding out what happens. Confusion is comfortable. It excuses you from the smaller, plainer, more frightening act of hitting send. Strip that away and look at what remains. What remains is simple, though not easy. Writing is yours to control. Choosing where to send it is yours. The act of sending is yours. What happens after — acceptance, silence, rejection, praise — is not yours, and spending your attention guarding it is wasted effort. Direct your effort only toward what you can still move.