Is there possibly any way to increase the drop chance of materials for building the barracks? I've put in hooouuurs so far but I'm struggling with everything- I've fought probably 20 ents at this point and gotten 2 ent logs, HUNDREDS of nightfalls and am at 43 broken traps/88 empty bottles, quite a few crazed druids and no luck at all so far with pure lunar water, etc. I'm trying not to give up but it's getting to that point :')

No way sry. To answer your question, you just need to be patient and never give up. :) Here's a guide I use. You can battle nameds but their hard but rewarding.

The LG is the current endgame content and was introduced partly to give players something to do and work at while additional updates to the site are done. The slow progression is by design. Buying high tier LG armor from other players can help make the fighting less tedious, though.

Best suggestion is to just pick up every chest/ore when you pass a filled node, since those can sometimes have higher tier materials in them. The grind will also get easier as you fight more since your attacks will rank up.
The barracks also have a material exchange which could potentially be useful for some things if you start to accumulate any pile of things that you don't need (though empty bottles, broken nets, ent logs, mender's talismans and ingots can't be bought)