My suggestion is to set small goals for yourself. Something that might take a week of time for you. After you have completed that goal then reward yourself with something else you want to dabble in. A goal like getting your class to 30 and a reward of unlocking all of leveling carpenter to 5 or 10. Your next goal could be leveling your subclass to 15 and getting your main job with a reward of giving the Gold Saucer a spin.

I have been doing stuff like that for the last year and it has helped prevent burnout. It also means I have yet to finish the MSQ I just cleared out Antitower this week. Just remember there is no pressure to do anything, so do what you want at your own pace.