One of the sure fire ways to overwhelm yourself is to create a To Do list that is as long as a legal size piece of paper or to create some super Excel spreadsheet with color tabs and tables.
A less daunting way to accomplish what you need to get done is to focus on mini batches of 2-3 things you need to accomplish and to make those items on that short list...well, short and to the point.
The mini-me list
One way I help myself be short and to the point is to literally write my mini to do list on little pieces of paper. Here's a block of notepad paper on my desk. Each note is 1.75" x 2.75". I can put these little pieces of paper in my wallet or pocket.
I can tell you that looking at mini paper literally makes my brain feel at ease because I think how big and stressful can something be when it's written on a minute piece of paper?
Now granted, small things in actuality can have big impact and require much work, but at least visually, seeing the line item on something the size of a matchbook helps ease the dauntingness one can feel when seeing large sheets of To Do list.