Our worldly successes cannot be guaranteed but our ability to achieve spiritual success is entirely up to us thanks to the grace of God. The best advice I know is to give is to give those worldly things your best but never your all - reserve the ultimate hope for the only one who can grant it.
A plant-based diet has actually simplified my life in so many ways. For breakfast I try to get my first serving of fruits and nuts for fuel. I'm completely addicted to coconut water for the electrolytes and hydration.