Meditation and mental self-regulation help from sudden attacks of envy. Find a quiet place, take a comfortable position, close your eyes and relax. Imagine yourself in a place where you were or will be well: at your grandmother's in the village, on the streets of an ancient city, on the ocean shore, on top of a mountain, in a forest on a meadow, etc. Immerse yourself in these pleasant sensations and try to hold them until you feel that you have had and will have enough beautiful days.