A platform to avoid bomb, large space for avoid spinning head. Camp / Heart Lamp. Some buff potion [Swift, Endu, Ironskin, Hunter for spotting] Get the wing and any speed boots. That should help the basic setup. Seafood dinner is easy to craft with useless fish like one to craft sting potion.
If it still fail, try to farm other mech for Hallow Armor and get Cross Necklace. If knockback is a huge problem, get the cobolt or better shield.