Time mangement for startup between full time job (i will not promote)

For those who have their startup beside a full time job. How do you handle your time managment and how do you reduce stress? I work full time as a software developer and have my own software business for already a few years now. As I finacially don‘t completely depend on my own startup I can do „fun“ projects as well from time to time without the pressure of having to succeed fast. But still the ambition and sometimes multiple other projects make it hard to handle the stress level beside the full time job and cause a lot of sleepless nights. The way for me to calm down is doing something with friends or family. But even then I have to force myself to not think about work. Do you have similar experiences?