I can't stress this enough. You are no longer running to a corporate schedule, and likely younger kids are unable to adhere to a school timetable without adult supervision. Regardless, kids or no kids, a schedule is imperative.
Make a schedule with at least three headings - you can call them what you want; just make sure one of them is "Work." Others can include Self-Care, Children, Housework, Social - whichever groups of activities you currently have on your plate.
During your work -time block, make sure that you turn off all notifications for Houseparty, Zoom, and any other social pages. While quarantine and social distancing is a thing, people are far more likely to feel the need to reach out to friends or even co-workers "for a chat". An hour can go very quickly.
Look at tasks that are the most important not to be interrupted. If you have kids, aim to schedule engaging/ activities so they can be on their own during that time. If you've got a partner, the odds are pretty good, that person is home with you. Maybe consider shift work? If you work in blocks of say 4 hours, you could both potentially achieve a lot.
If you're a single parent, clearly communicate expectations to both children and your employer. You'll need flexibility from your employer to address the needs of any children, so make sure that you're proactive, and you let team members know what to expect from you. On the flip side, be sure to let children know what to expect from you when you are in "Work-time".
Unfortunately, we are not in a position to change our circumstances. But scheduling in Self-Care is essential for our wellbeing and our ability to cope with the many hats we suddenly need to wear.
Your Self-Care is something you should schedule into your day to make sure that you do take a break, whether that be cooking, a hobby, an exercise, or just being still. Self-Care during these trying times is a whole other subject, but for now - let's schedule it in and get used to it having its own time in your day.