Truly accept the meaninglessness of life. Then choose a meaning for yourself. Here’s a good one: help reduce the amount of suffering in the world. Millions of people around the world are in a constant state of suffering (poverty, homelessness, war, mental issues, etc.); they’re not lucky enough to have their fundamental needs met in order to contemplate the meaning of life. Help just one of them to have a better life (donate, volunteer, mentor, ...). It shouldn’t be too hard; look around you.