People are consumed by setting priorities. They make to-do lists and carefully note whether it's an "A," "B," or "C" priority.
Here's a question: have you ever gotten to the "C" priority items? Probably not. At least not while it was a "C" priority. Of course, once it became an "A" priority, you got to it, but not before then. The "C" priority dental checkup you didn't schedule? I'm guessing you got to it once you needed a root canal. The "C" priority 60,000 mile auto service? You definitely handled it once your car broke down on the highway. The "C" priority phone call to that customer you don't really like? You probably had to actually visit him once he cancelled his next order.
You've got an infinite amount of work to do and only a finite amount of time in which to do it. So when stuff comes into your system, you shouldn't waste time carefully calibrating its precise priority level. You need to make a simple decision: Are you going to do it or not?
If it's important enough to do, figure out when you're going to handle it. Maybe it's not critical, so you won't do it for three weeks. That's fine. But make a commitment to do it. And live up to that commitment.
But if it's not important enough to make the short list, then give yourself license to dump it. Maybe it's something you would do if you had more time, or more energy, or if your mother would notice -- but since you don't have that time, and since you don't have to tell your mother everything, be realistic and drop it.
Once you make the decision to dump some of those items that have been festering in your inbox or rotting on your desk for six weeks, you'll feel better. You'll gain a powerful sense of control. And you won't have those incomplete to-dos glaring reproachfully at you, reminding you of your indecisiveness.
It's not a perfect world. You can't do everything. Even if you give it a "C" priority.