I forgot what's all over there, but you still should be able to move around. Jump on objects to avoid the water, just keep looking for the upgrade so you can go in it. If it's glitched and you can't move at all without dying, you may have to restart.
I am wondering if I need anything else besides double jump to make it back up from the abyss (down) because I cant make it! Please help.
Get all the upgrades, then you can escape. You'll need the others anyway, to destroy purple and gold doors, go in water, move faster in water, and avoid dying by enemies.