Free time planning & guilt

Hi!  I have a full time job. In addition, I’m working on my side business on weekends and evenings. Therefore, even when I schedule some free time to rest I feel guilty (my T is that I’m wasting this time) and I’m not able to figure out what I should actually do (sleep, go for a walk etc.)  As a result, I constantly feel tired, stuck and unproductive.
Could you please advise how to schedule an appropriate amount of time in order to have some rest and figure out what to do?  Many thanks!