Antlion can't be done now, you will need to come back later.

Don't worry, those orange crystals take you back and forth in no time

If I was you I'd go back into the mines, to that stretch that has only skeletons and chain at least over 50 of them. You will get a cool Sky Pilot's Den trophy and a bunch of bone fragments to sell for $199 gil a piece. This will allow you to buy good stuff later

Chaining wolves at Eastersand, and / or walking north till Nalbina town will also allow you to find or buy better weapons.