Your brain is not a good storage unit; too many good ideas get lost or come up as a distraction when you are in the middle of something else. What I am most bothered by is the concept that I might never get caught up or that my to-do list is endless. What I have tried in the past is to work harder, longer and faster to catch up. That strategy has not worked for me at all. I end up doing nothing because there is too much to do and I cannot imagine where to even begin. I have finally learned to try a new concept to get out of overwhelm. I slow down. I stop and sit and plan out my actions for the day or week instead of frantically doing things.
Try this first step. De-clutter your brain by writing out on paper all of the things you want to get done in a set time. Just write everything that comes into your brain. It helps to write everything on a separate piece of paper so you can organize them later. The main idea is to empty your brain.
Now the easy part is done. Next take every idea and sort by category. Now what I do is to move all the like items together and make piles, files or action lists based on everything I wrote down. It still can get messy. What I find is that getting it all out of my brain really helps me see what I have as projects and what things are easy to click off of my to do list. Try this and see what works best for you.