Crystal mines dilemma

So, hi everyone, I'm new to the game (hollow knight) and I'm trying to play normally without watching any play throughs . I'm already opened the green mossy location (I forgot the names) and mushroom location, fought false knight, hornet ,brooding mawlek , guy mother and massive moss thing . I bought a lighter from sly and opened crystal caves , and I'm getting COOKED down here , so I wanted to ask , is this a skill issue? Maybe I need a better nail first ? Please tell me if you have tips and tricks for this , thanks y'all in advance ❤️