Sometimes — not always, but sometimes — it’s good to defer relaxation. By deferring relaxation, you make the quality of your relaxation time better, even if the quantity is somewhat smaller. By ‘quality’ I mean a feeling of satisfaction while you are relaxed, rather than an ever-present sense of guilt over what you should be doing, but aren’t doing as you ‘relax.’
It’s very bad to have relaxation/refueling become associated with guilt. The two should not be mixed, and don’t have to be. Either you have objectively earned the relaxation time, or you haven’t. (You have to be the objective judge of this). If you have earned it, then fully enjoy it. Send guilty thoughts away. If you haven’t earned it, then change from the relaxation to your ‘to do’ list. Then go on, later, to the earned relaxation.
Spend time actually thinking about how much relaxation/refueling time you need and deserve. Then be at peace with it.