Kiss your loved ones and everything you know about life today goodbye. IF you survived the initial exchanges you would face death daily in a harsh environment with little or no food, wrecked ecology, anarchy, raging fires, no power, no infrastructure, no finances, and no communications. There’s not much that can be done - if you have a chance you could try to flee as far from humanity as possible and teach yourself how to live off the land with no food, medicine, or shelter. Even then the ravaged environment would be too dark from dirt, smoke, and ash for sunlight to penetrate enough for crops to grow.
