I think I know where you mean the enemies are really difficult in that part.
If you've kept a save point where the three portals opened up then warp back to Pulse and do that side quest with the crystal thingys. You'll get some components to upgrade weapons and some chrysterium points. Also, fight some Adamanchelids for Gold Dust. I think it sells for something like 20,000 gil so you can buy crap to upgrade with. Same goes for cactuar dolls if you get some, I think they were about 10,000, but they hardly ever seem to drop.