I hate to say it, but your way isn’t going to work. There is nothing wrong with your way, you don’t slack off too much (unless you actually slack off too much), you’re not in the wrong place, and the deck isn’t stacked against you. However, if you think you can go about becoming the best version of yourself when you feel like it…..then just give up now.
Slotting your life’s work, what you bring to this world that only you can bring, into days and times that are convenient for you is ludicrous. Hate me for saying it. You don’t get to decide what and how much this currency this personal, living entity needs. Everyone has one and it’s got to be watered, nurtured, given sun and allowed to breathe.
Do you tell your flowers when to grow? If you did would they listen? Did you pick the color of your dog? Things of nature, things of beauty are creations of God. It’s growing inside of you and you have to take care of it. This is corny but it’s true. What you have inside of you is meant to flourish under your care and then be given to the world. Have some respect. Don’t try to slot it in when it’s convenient for you. Your instrument, craft, has its own needs. It’s an actual thing, a part of you that needs to develop and grow. It’s precious. You need to love it, cherish it, and attend to it. So get out of the 9-5 mindset. That won’t work here.