Imagine a good future, always. Seneca, Epistles 2.13.10-11

Do not put effort into imagining your future suffering. This does not mean that you should avoid taking rational precautions. But once they are taken, you should stop thinking about the possibility of ruin. When you are in position, when you have made your decision, relax. And think about something better than impending doom. Be cheerful, even when you lose.

Inquiramus itaque in rem diligenter. Verisimile est aliquid futurum mali: non statim verum est. Quam multa non exspectata venerunt! quam multa exspectata nusquam comparuerunt! Etiam si futurum est, quid iuvat dolori suo occurrere? satis cito dolebis cum venerit: interim tibi meliora promitte. Quid facies lucri? tempus. Multa intervenient quibus vicinum periculum vel prope admotum aut subsistat aut desinat aut in alienum caput transeat. Incendium ad fugam patuit; quosdam molliter ruina deposuit; aliquando gladius ab ipsa cervice revocatus est; aliquis carnifici suo superstes fuit. Habet etiam mala fortuna levitatem. Fortasse erit, fortasse non erit: interim non est; meliora propone.

Let us examine this matter carefully. An evil in the future is only plausible or likely: it is not yet real. How many things have arrived unexpected, unforeseen! How many other things have yet to manifest, though they have been expected a long while! Even if something wicked really is going to come, what use is our anticipating the pain it will cause? You'll hurt soon enough, when it arrives. Meanwhile, give yourself better things to hope for. What shall you gain by this? Time. Many moments will arise in which some nearby danger subsides, though it be very close to you. It may even pass away, or pass over to some other person. Fire opens the door to flight, and ruin generally puts some folk down gently. One man finds the sword recalled at the last moment from his neck. Another outlives his would-be butcher. Even ill fortune has a sense of humor. Perhaps it will happen; perhaps it won't. In the meantime, it isn't here. Look at something else, something better.