The only problem is i cant get back up from where u came from
The only problem is i cant get back up from where u came from
Why not? Did you use the Save Crystal on the screen where the party splits up? If so, you may have encountered a rather annoying glitch that prevents you from climbing up the pillar, thus rendering you well and truly stuck.
If that isn't the case then there's no reason why you cannot exit the Northern Cave.
EDIT: Remember where you found the Save Crystal in the chest? The hole next to it leads up to the Highwind. Go through it and climb a couple of steps, then head for the Highwind and climb the ladder.