Visit the swamp post haste to trigger the other iron-tier raids. Also, if you've beaten the elder you should have access to lvl 3 bronze buckler and weapon (spear is best vs. trolls but I understand most people don't main a spear). Take your bronze weapons and visit some troll caves (if you haven't yet). The troll caves force you to fight them in melee. This will build your confidence as they are very killable in melee, and in a shockingly short timeframe. With your new troll-slaying skills you should be able to kill troll raids before they even get near your base.