For me, the hardest scenes to write are the ones about either touchy subjects (such as mental health), or scenes that are meant to invoke emotion from the reader.
For instance, I tried to write a scene involving a panic attack with one of my main characters, and for me, that was very difficult. I had to go over the script several times to ensure that it wasn't making a mockery of the ordeal, and I think I'm pretty happy with how it turned out. The room twisting and closing in, creating a claustrophobic feel while Daisy struggles to breathe, invasive thoughts echoing throughout her head and causing and avalanche of negative emotions...
I didn't quite capture all of that in the original novelization for Reaper's Storm, but I think I did an okay job in the comic
(The chapter in question: https://tapas.io/episode/3113135)
There's also a scene coming up involving a character's death, and for me? That's a very important thing to handle. A death should feel as though it meaningfully pushes another character forward (or backwards!) in a way that couldn't have been accomplished without said character dying. A death shouldn't make a character feel like a throw-away side character, and for that, you need chapters upon chapters of character development, experiences, etc. to make that character feel like someone should care about.
And if you make the scene too horrific, people may just stop reading, especially if that character was their favorite one. So there is a LOT of anxiety that comes from killing off a character. I'm really hoping I can pull it off, though!
Finally - and this one gives me the most anxiety - is an entire character arc coming up involving manipulation, sexual assault, and overall being taken advantage of. That is a VERY touchy subject, and I am very scared that I'll screw it up. I've asked myself again and again if it's necessary for the character to go through, but I think that it is. That will probably be the hardest scene for me to write, and will probably undergo upwards of 10 rewrites per issue.
We'll see how things go, though. I'm very much looking forward to sharing my story with everyone :>
(You can read it from start to finish here)