I hope that Dark Souls 3 ends up being better balanced than this. At least once the inevitable DLC arrives anyway. This isn't necessarily a complaint about The Old Hunters, but the balancing on it seems rather skewed. Unlike Dark Souls and Dark Souls 2, the DLC weapons and enemies are far from balanced with the main game (Artorias could have its spikes, but it wasn't like this).
It's been recommended to be at least level 65 before trying the content in this. However, level doesn't seem to matter as much as having +6 - +10 weapons with some of the best gems you can get from the main game/Chalice Dungeons. The enemies are ridiculous damage sponges that make it feel like even the heavy hitting weapons (+6 at least) are just doing the needle-prick damage of the Threaded Cane unupgraded, while the enemies hit you for 30% - 50% health per hit. Yeah, there's always trying to parry. When the game actually allows it. The circular, horizontal or diagonal swipes done by the early hunter enemies seems entirely random as for what the parry window is. Or there's some kind of resistance to it that I don't know about. Anyway, it just kind of seems like the enemies are NG+ or NG++ in difficulty by default.
You suffer through that for a little bit, and then you can grab the Beast Cutter. Still doesn't really help with that area much, but it's extremely strong for vanilla areas. Then, a few minutes later you can become one with the power of the pizza. Some people were complaining about how broken Ludwig's was for PvE, yet this thing just owns it in almost every conceivable way in vanilla content. No thrust attack, but so what?
You have to remember that the DLC came over half a year after the main game so From is expecting those who buy the DLC to already be quite far in the main game. That's why it's more difficult. The difficulty should also be an indicator that if you can't manage then you should level up, just like many parts of the main game.
That said, while the difficulty is probably ok for NG, in NG+ the DLC doesn't scale very nicely. Anything that is not at least a +8 weapon with good gems is close to useless against most of the normal enemies whereas the main game seems to be a bit more forgiving.