It can be useful to think about why you feel so unmoored...Often this can be linked to a sense of anxiety and learning to be OK with doing nothing means learning to trust that nothing bad will happen as a result.
The need to be busy and feel needed can also be linked to missing a sense of meaning and purpose in one's life.
Our society has really pushed the idea that being busy, constantly active, always doing and being always 'on' via smartphones, text, emails and social media, means that we're achieving and gives us a direction and purpose through a series of goals.
If you're struggling to let go of some of this, it can help to realise that living life at a slower pace, doesn't mean your life lacks meaning.
Don't think of it as "doing nothing" or "wasting time", reframe it as establishing a new set of goals. These goals are to teach yourself how to live a more mindful and meaningful life, to accept self-kindness and learn to be more present in the moment.
I live a quieter, slower life now, but it's much more balanced and I still have room to pick up projects and interests (I get bored easily), throw myself at supporting a friend or family member or deal with a crisis when needed, without expending energy I don't have to give. Consequently, I'm more content than I used to be and more comfortable with myself...I don't need to constantly prove myself, for example.
It's a bit like the speedometer on a car...Most of us drive day to day at 30-50mph, which is better fuel economy. When needed, we speed up to 60, 70mph on appropriate roads. We don't need to drive at that speed all the time. Recovering from burnout is a bit like learning to pootle along a country road, enjoying the scenery, rather than always hitting the motorway 😁