I would calculate that fully one third of my creative day is spent overcoming inertia. I used to panic at the block, thinking it was permanent, immovable. It would grow and consume me, it was painful. But now (after some therapy, mind you) I find that though I am still struggling to start things, I now view it as part of the process. And accepting that has relieved the unpleasant grip on my stomach.
Now I structure my day by making a list of goals (well in advance of their due dates) that I don't expect to check off in order. Rather, I can sort through and pick from the list with the understanding that I have the right to leave undone any of the tasks without consequence as long as they are not part of a deadline.
This does not relieve the pressure, but it does feel more organic and more workable than a rigid timetable. It seems to leave more room for creative thinking and room for things to happen that I didn't plan for. Things like making an unexpected online connection with helpful information or a like-minded person, or thinking of a new object to make. It leaves room for the anxiety to roam around in a broader pasture which keeps it occupied and far enough away sometimes just long enough for me to grab a project on the list and start it.