Gaia is old already.
Lovelock says there are no more than 500 million years left!
Whether that is much or little depends on what you want to achieve in life.
But it is not Gaia that sets the limit. It is Helios, the sun. The sun gets warmer too and will ultimately, as a red giant star, engulf Gaia and leave nothing behind.
Does this help you to get a perspective on your own life, to focus better?