Story time!
I have been seeing a lot of discouraged new and old players alike, and they all remind me of myself when I first started playing almost exactly 4 years ago. We travel back to the Moonfire Faire of 2020...
When I first started playing FF14, I was abysmal at it all. AOEs were an entirely new concept to me, as were the actions and traits, controls, and of course any game-specific mechanics. I had friends at the time who carried me through all of MSQ until I reached endgame around patch 5.4.
I think I cried even more times about how bad I was doing than the MSQ itself. I have severe mental illness affecting my cognition and chronic illness including chronic pain, this was my first MMO, I'd hardly been playing video games at all besides some Nintendo stuff, and I just have a notorious reputation of being really, really mean to myself.
My friends liked to joke around about my mistakes, too, which sometimes hurt my feelings and other times cheered me up because I knew they weren't taking it seriously; they weren't actually upset at me or bullying me.
Eventually I got fed up with myself and how I loved the game, but at the same time felt dread whenever I logged on. I decided to start really learning my job, bit by bit by bit, and it took a long time but I started to get better. By the time Endwalker was released I was doing much better at the game as a whole.
At the end of Endwalker, I was able to do the current extreme trials, although for the second-to-last one in the expansion, my friends absolutely had to carry my corpse through the last mechanic or two, haha. So, this happened over the course of 2+ years, probably. And I continue to learn and improve every day.
The point of all this is to say, please don't give up.
In a point in my life where I rarely leave the house or am able to do things to take care of myself, FF14 has given me the chance to prove to myself I'm not actually incompetent like my brain's always telling me. I want it to do that for you, too, if at all possible (and I really believe it is, and I don't even know you!).
It took a long time but I was able to turn that energy 180 degrees on myself and use it to motivate myself to get better. It took patience, determination, persistence, repetition, a bit of reading and video-watching, and some other stuff I'm probably forgetting.
Please give yourself as much grace as you can (easier said than done, I know) and be patient with yourself. If you have an experience with a toxic player, I'm really, really sorry. I've had a few of those myself, but you can't let those people win! You can't let your own self-criticism and helplessness win!!! Prove them wrong, and mentally stomp on their faces while you do it!!
Keep going and keep trying to improve because it will pay off, I promise! You CAN do it, too. You got this! <3