Cats need to learn how to schedule. Wake up early, get 2-3 hrs in before work and then set yourself up for a full session after work. Drink Red Bull, consider hard drugs (just joking.) Stay away from bath salts.
In all seriousness, it's possible to schedule a full 8 hour music day. The only problem comes in when you have a wife, girlfriend or child you have to deal with. If you don't have any of that, then you should be good to go.
If you keep bitching about how tough it is and you can't find the time, it means you don't really want to do it.