CGP Grey has a good post on dialing down the volume of self-invited Internet noise for a month. On letting in too many little inputs over time:

Arguments about the quality of news aside, he came to realize the ‘overwhelmed’ problem wasn’t about the number of things to do, but was about the number of things he let into his brain. The news is a rather effective vehicle for delivering a large number of small things: each story a single guest arriving to a party.

Individually the guests don’t make a lot of noise, but adding one by one makes the collective volume creep up in a way unnoticeable until you take a break from the conversation and realize that it’s way too loud in here.

The solution was to kick most of the guests out and be more careful at the door: college-me stopped reading the news and cut back on TV. The number of non-actionable things on the mind decreased, and with that did the amount of ‘overwhelm’.