I’m a long-time user and big-time fan of budgeting software YNAB. One of the things that’s great about YNAB is that they don’t just provide software: they also provide a (free!) mini-course on how to budget well. One of the YNAB rules for budgeting is “roll with the punches”.
The key idea of the “roll with the punches” rule is that budgeting your money doesn’t mean that you must 100% stick with your intended budget on pain of death. Priorities change, the information you have available to you changes, and a smart budget changes in response. If you have no money left for eating out but an out-of-town friend you haven’t seen in years is suddenly in town and invites you out for dinner, of course you’re going to go out, and you change your budget accordingly. (The trick is to remember to re-allocate some money from a different category in your budget: otherwise you’re just living beyond your means.)
The same thing goes for how we budget our time. Many people get an odd kind of anxiety when they make themselves a to-do list and then don’t get everything on it done. Maybe other things came up (new information). Maybe you actually just really needed a break (new priorities). Maybe something took much longer than you were banking on (new information). That’s OK. A smart to-do list (time budget) changes with changing information and priorities.
If you keep to-do lists, then the tasks that you didn’t get done today just go back onto a to-do list for another day. You haven’t neglected them! They’re still there, and you’ll still get to them. Unless at some point you decide they’re not worth doing, which is often true of tasks that we postpone over and over again.
Either way, breathe. Be kind to yourself. You haven’t failed; you’ve adapted to new information and new priorities. That’s not failure: that’s success.