I will enjoy life when I will just have this little nap, recover from illness, get my acts together, fix the relationship trouble etc.
Makes sense. You can indeed feel better when things will fall on place (maybe. Your bad feelings can come from a different source and you are mistakenly attributing it to these things).
But you got to enjoy life meanwhile. Much of life is spent before we got things right. Even staying in line or waiting in airports.
Multi-strategy in life management.
Having a single strategy that is limited to only part of life is not good. It means that when the situation is not suitabgle to your strategy you stay a sucker. "If I am too tired I feel bad no matter what" means balatantly giving up.
A set of strategies for varying circumstances is more realistic.
What counts in life, is what difference we can make. Possibly, one can improve feelings in bad times even more than good times (then you feel good anyway). But what counts is the difference, and a difference there is is bad times, too.
trouble gets superimposed on us. Why? Any escape? (linked above under "Even staying in line or waiting in airports")