Aahh, I feel like an idiot when people say this game is too easy cause I always end up getting my ass handed to me a lot of the time on normal. I don't think I'll be getting very far with this DLC when it comes out for the PS4. Or I just really suck at playing this game XD
Both the story and encounters in JoH were a ton of fun, I hope you give it a chance!
I played on Normal, too, and can see how some of the fights could still be difficult. If you're not already using them, a few crowd-control skills could make a huge difference for you.
In the base game I could run into almost every fight with my two-hand elf warrior lady and just facetank/Whirlwind the crowd into submission but in JoH I opened most fights controlling Dorian. Static Cage kept assassin-types from ambushing, shield-types from charging, and despair demons from hopping all over, on top of lumping everyone up for some awesome AoE damage (Lavellan could finally go nuts with Whirlwind, mmm). Also Horror is great because it lets you disrupt entire groups of enemies that are giving you trouble, like archers/mages picking you off or brutes doing their knockdown AoEs. There are a ton of crowd-control options beyond those two skills but even just using those two helped me a ton in JoH. Taking passives like Clean Burn, Gathering Storm, and Flashpoint will shorten the cooldowns too so you can use them very often
Oh, I'm pretty sure Cole was running around putting people to sleep, too, but I don't ever switch to him so I just let him do his thing.
Now I can't wait to do JoH on Nightmare, it's going to be fun!