Hey Jacob, thanks for bringing up this topic, I’m really enjoying reading everyone’s responses.
First off I want to congratulate you for giving your newfound free time some serious thought and not succumbing to Netflix! 
I can totally relate to the questions you’re having and I’m still trying to find a good balance between trying to fill as much of my freetime with productive learning and enjoying seeing friends and family, relaxing, etc.
One thing that I can definitely recommend trying is to pick something you enjoy but takes a lot of concentration (like developing your design project ideas or portfolio tweaks) and wake up one hour earlier than you usually do every day to dedicate time to this task. It’s certainly an adjustment but stick with me for a second because there are a few huge rewards for your sleep sacrifice.
First, you will be super dedicated to this task because you are actively making a minor lifestyle change to work on it every day, it is literally the only reason you’re up that early. Second, since you’ve effectively taken this hour back from when you would normally not be doing anything else, you don’t have any other obligations to juggle. Finally, for both of these reasons, during this hour you are more focused and you will get a lot more done in less time, plus you get to start the day off with a win! Then later when you come home from work you’re free to focus on your athletics or anything else you want.
The only time I’ve tried this was/is during my learning sketching journey here on the forums and I’ve been really happy that I gave it a try, now it’s part of my daily routine! Best of luck finding out what works best for you!