Noob question: How to pump resistance?

I have like a 20% resistance in everything and I'm dying to sh*t immediately.

I have some idols that I could swap out but I'd have to halve my DPS just to get one or two to 70%

I can't put anything else into equipment because they all already have two suffixes.

I could nuke all affixes from my current equipment and reroll everything I guess but I'd run out of crafting materials pretty quick if I have to do that for every new boss that uses a different element. Is that just how the game works??