It is easy to be overwhelmed - by time crunches; critical feedback/things to fix; work demands; crises (big or big-in-my-head); conflicts; anxiety; fatigue... you name it. There is always a big ugly something waiting to pounce and wrestle our good intentions to the ground.
Do something vs. be overwhelmed by the enormity. Inertia can lead to paralysis.
1 - Picture the desired end state... and then the first small step to move towards it that can be done immediately. The end state may shift but each small action moves us further away from the big ugly something.
If you can't see an end... don't let that stop you from creating a beginning.
2 - Share the goal and the fear with a trusted friend. Nothing makes the monsters under the bed look like dust bunnies faster than daylight. This can count as a first step :-)
3 - Prioritize with your own criteria. Easiest...fastest...most impactful... it's your choice. What one task will ease the stress first?
4 - Delegate. Who else needs to/can be involved? Big ugly hairies rarely involve only person. Negotiate support.
Don't wait for a plan to be in place. Don't wait for the stars to align or better choices to come along. Ingredients in your pantry don't become cake until you start moving things to the counter. You can change your mind /plan at any time; just keep momentum.