My rule of thumb is that we have 100 (24-10)*7 hours a week to manage. I arrived at the 10 hours downtime / day as sleep + grooming + essential eating. It appears that you work for half of those hours. I admire you for allocating time to work out and spending time with family. You don't mention how much time is taken up by commuting. If it is more than 20 minutes then I would suggest audio books, etc as way of being more productive during your commutes.
If I were in your situation, I would try to get an hour each evening to read/learn. Then perhaps two blocks of a couple of hours on weekends to work on your hobby, etc.
The obvious solution is to do everything at the same time and to connect whatever possible sequential vs parallel execution. If you're go to workout in a gym, so buy things after and in the meantime make your things like readings and call whomever needed. I can't even imagine, but wife says I have to learn.