A good hack to this is to wake up earlier and work on your stuff first thing in the morning, allows you to spend that first energy on your real goals, and then you can move to other stuff. It's fucking hard for me to wake early, but I really need to get back to doing this.
Edit: another advantage of this method is that you can have guilt-free relaxation on the end of the day.
I used to wake up at 5am to work on my side project (blogged here[0]). It really is the best way to go if you are serious about a side project. That blog post was from 7 years ago. I again did the 5am stint recently and only lasted a couple weeks. Although my day job now is much more stressful than it was back then, so I think that is a big factor (along with being seven years more tired...)
Edit: another advantage of this method is that you can have guilt-free relaxation on the end of the day.