Kandoris

So i was progressing through story i just beat the 8th gym so i went down to dark cave, but i forgot i dont have a pokemon with rock smash so i exit dark cave and try to go back but there is ledges blocking my path so i cant go back to blackthorn. i know i have to struggle to death or get all my pokemon killed by a level 3 zubat but is there a different way to get out?