parsley seems to be turning brown and dying
Hard to exactly diagnose with physical examination, but here's a suggestion: simply cut it all back, to within a few inches above the ground (i.e., cut off most of the leaves). If the plant was just over-watered or over-fertilized (or whatever) it will grow back - in a few weeks you'll have enough new parsley growth to harvest. If the plant does NOT come back, it was probably too sick -- and nothing you could have done would bring it back. By the way - you can (and in fact SHOULD) do this with all herbs - keep cutting it back throughout the season; most herbs will keep on growing/sprouting new growth!