If no ones already asked, why does not being ''good'' at this games normal content affect you? Does failing in other games give you the same kind of grief? Is it more a matter of feeling like you're letting others down? Does it make you feel less intelligent when you cant figure something out right away?
Before looking at outside reasons why you aren't happy, ask questions about yourself and why you feel the way you do. I say because I used to be that way when I was new. I mainly play healer, and I was so nervous about playing with others I would solo unsync dungeons and even the early trials, dying until echo was strong enough to carry me through it. But after experiencing some pretty bad dungeons with tanks that never used tank stance, didn't AoE at all or even had no tank period cause they left at the start and we never got a replacement and we still beat the dungeon, i realized ''I guess I can actually do this'' And as more time went on and ive played with all kinds of players, ive learned to find peace with the things im not good at and just be happy about the things i am. And the only people who would ACTUALLY be upset about messing up in normal content are the people who spend most of their time in tales of the duty finder.
Theres also no shame in asking for help if something isnt clicking. Our brains all work differently and there have been simple mechanics that I just blanked on for ages (cough sharp turn) Like when I wiped us on sunken temple 3 times cause I didn't understand doom, and I finally asked my more than patient party ''whats going on?''
All the people who have been saying ''its okay to fail'' are absolutely correct, you're going to fail at a billion more things in life in and out of videogames. The difference is, in games we get to try again and again without consequence.
I personally don't think DT is too hard, heck the stormblood dungeons have harder wall to wall mob pulls than DT, especially since we have so fewer abilities. The one thing I would agree on is when someone said 8 seconds of stun in that 1st expert dungeon boss is too long when getting hit by the dolls.