I think this could help.
1. The point is not to "do what you love", but to "love what you do".
Trying to do what you love is destined to fail quickly: there's always something else, there's always a part of the job you don't like, and you never truly have control over the very fact that you love something or not, at least not if you approach it like that — you'd be condemned to follow your emotions as the only decision maker for your choices in life. But emotions are meant to guide us (it's information, just the language of the body), not control us.
Loving what you do, however, is a totally different process, and quickly becomes a choice as you flex that muscle: essentially it's about putting "good will" into all your actions, it's about this idea that "how you do anything is how you do everything"; to sincerely try with an open mind and being positive about it. Several things follow from this simple practice, mindset:
- we are creatures of habit, and the more we do something, usually the more we like it. It's just how the brain is wired — that's how marketing works, by sheer repetition, law of numbers. Propaganda and manipulation as well. "Self-programming" yourself to be able, in time, to grow positive feelings about anything you have to do is really a sort of superpower in this day and age.
- Here's an equation: effort + love = mastery (alternatively, you may see grit + passion = skill, any variation like that). The message is clear: lots of effort (time, regularity, repetition) and lots of love (but that part comes from the doing, it's mechanical unless you resist it) is how we build ourselves, and happiness among other things follows from that (because nobody can take away such happiness from you, it's internal).
- It seems that we all score differently on that scale, the term is conscientiousness, but it is my belief that it can be trained by force of will + action, i.e. determination (to commit to do it, whether you are "motivated" or not, regardless of emotions) + effort (marathon: paced, sustained, repetition, long-term).
It takes about 20 days to break a habit, and 3 months to form a new one. Probably about a year to make it last virtually forever, unless detrained.
These simple things have huge effects over the psyche (happiness notably) in the long run. Massive compound effects.
2. Another thing is the idea of "meaning", purpose, the "why" we do what we do. As far as I'm concerned, this matter is solved: you create meaning for yourself. That's it. We all make a patchwork from bits and pieces from all over the place, and it may appear of its own as a child or never for a lifetime, but ultimately, it's a conscious act, a decision you make. Meaning is the result of volition, internal drive to give substance to the world; those who seek it externally may be amazed at others but probably feel empty themselves until they become the creators of their own interpretation, their own meaning. Purpose is what you say it is.
The short TL;DR is that if you picked up anything and worked diligently at it for 10 years, you'd come out the other side an expert and loving it (average/normal human response to that situation).