The exercise of the day: be Zen when your workload is ridiculous. We are such a society of worriers. I am guilty, too. My workload right now is huge, which is great on one hand and stressful on the other hand. How to keep up with the wheel that is turning faster than I can run? The art of not pulling your hair out when your need to pay your bills is more important than sleep? (I'm kidding ... sort of ...)
First and foremost -- surrender! You will not get it done in one day, so don't keep that as a goal (that is crazy and unreasonable). Quit fretting and thinking about it. Just let it go. Think of blowing a dandelion to the breeze.
Second, think of it like biting an elephant one at a time. You can't swallow the whole elephant, right? Just get into what I like to call "task-orientation" -- one task, one step at a time. Then walk through each task, finish one, and move on.
Daily, weekly and monthly goals work great. Don't look at the entire GOAL, but rather go day-by-day, one goal at a time, one task at a time. Finish the goals list for the day. Move to the next goal for the next day. Pretty soon, you'll finish your weekly goals that turn into a monthly goals completion.
Communication is key! When you're working with clients, make sure you communicate. Most people are very understanding. Let clients know you are working and their projects are getting addressed and quickly as possible. Under no circumstances stop communicating. Clients are given two bad impressions: 1. you don't care and 2. you're not working on it.