If you can't stop the (possible) coming disasters, what's the point in paralyzing yourself with fear? Do what you reasonably can to prepare, and enjoy the life that you have now while it's here.
Things will certainly get worse, and disasters will happen in the coming decades, but the end is not right around the corner. The decline will be slow, and it's still possible that solutions, or at least mitigations, will be found. Look for little ways to contribute something positive, and try to appreciate the moment.
Not exactly the best example, since that's not a typical behavior but a result of poor scientific practices. Mantises only take that action when extremely stressed, which is frankly a lesson we should be carefully considering.