Ok, I am the worst. Looking through pathfinding again and trying to see where I had spots I could optimize, I noticed that the closedList looked mighty big. Digging through it deeper, I saw that it had repeats, even though it's not supposed to. Turns out I forgot to exclude the closedList coordinates from my pathfinding. The pathfinding is now ridiculously faster than it was before, and doesn't even hiccup when moving across the whole 200x200 map. The good news is that after a month, I've finally gotten through the hard stuff and now can move to combat without worry; bad news is obviously that it took a month for me to figure it out (well, a few days if we count actual days thinking about it).