A beginning adult student said to me:
"I think the biggest lesson for me is that this is going to take a long time. I like instant gratification, and the ego likes that too, right? But with continued effort, eventually, there will be music."
Yes, it might take a long time. It might take a long time before you sound good. It might take a long time before you are happy with your playing.
How high are your standards? Of course, the higher they are, the harder it's going to be to reach them (Why did you set them so high, anyway? Who told you to do that?).
How smart are you? Because you know, the smarter you are, the more you will realize how short you are falling of your standards, and the harder it's going to be...
I wish there were a quick way to get there, but I haven't found a shortcut. What I have found are (a) slow ways that work, and (b) ways that will waste your time and make you so frustrated you will eventually quit. So, at best, it's slow-going. This stuff is just really hard. Why do you think most people can't do it? But you can do it, you know. It will just be slow. Like a lazy river.
Now, you like instant gratification. You're certainly not alone. You say the ego likes instant gratification. What I would like to ask is: who is labeling instant gratification as bad? Is it possible there is one part of you who seeks instant gratification, and another who labels it? Which part is the ego, and which part is the one who lives only in the moment, experiencing without evaluating? Actually, I wonder if there is no gratification other than instant (it's not like oatmeal). What is delayed gratification, apart from a story you are telling yourself about the future, about yourself and the meaning of your actions?
When you were a child, did you have any problems seeking instant gratification? When did you learn it was a problem? Who told you this? Do you believe it 100%, or is there any part of you to whom it's news, who maybe even feels hurt by it?
If you're not being gratified, why not? Really, pay attention to this. Is there anything there, in that space between when you try to play (and fail) and when you get frustrated with the whole thing? You're allowed to be frustrated, you know. You're allowed to want this to be fun.
What would it look like if you didn't label it? If you played an exercise, messed it up, got frustrated, and just kept going? Is it even the playing that frustrates you? Is it the lesson? Is it when you're in the shower thinking about playing? It's so easy to label the whole thing. But frustration happens at a specific moment in time. What is triggering it?
Can you just make it fun? Just take it. It's yours, believe it or not. Does your hand hurt? Then stop doing whatever you're doing that makes it hurt.
"But then I won't play it right."
Yeah, you won't. But your hand won't hurt anymore either. You decide.
"But if I don't work hard and make sure it's right, I'll never get better."
Why do you want to get better, anyway? You've already said you want instant gratification, and if working hard is preventing you from getting your gratification, how much do you really want to work hard and get it right, anyway? Why are you telling yourself you do? Look, you're going to get better if you do the exercises. It's my job to worry about that, anyway.
So again, can you make it fun? Can you find some pleasure in the physical movement, regardless of the sound? Can you find some satisfaction even in the ugly sounds, knowing that they are the result of your body's own freedom? Even if you don't play a note, can you find something right there, in that place where you know that you have the power to move as you see fit, or not, depending on your whim?
If none of that works, can you just stand up and scream? Would that be fun?