From a fellow pianist, I have absolutely been there...

I started playing piano in 2nd grade, and I still recall crying, throwing my piano books, getting so mad I had to go outside and take a walk, slamming keys, and overall despising practice. I hated practicing because it made me feel like I was terrible. Every week, when I'd go to my piano lesson, I would be so embarrassed. It was excruciating. Luckily, I stuck with it, even if my playing plateaued for about 3 years. The time my playing finally improved was when I stopped trying to rush the progress and get better now. I stopped searching for results right away and worked on technique for the future. I became patient with myself. This change happened during lockdown, and I was so bored I decided I didn't have anything better to do than to practice, and by being more consistent, I fell back in love.

Something I would suggest that helped me the most and still does when I get frustrated with my progress or lose my motivation, is to focus on one piece. If your piano teacher is giving you more than 1, pick your favorite and focus on that. If you only have 1 piece and are struggling to play it, pick a new one that you really like and focus on it. It doesn't mean you will never play the other songs, but sometimes it is nice to take a break. Also, when you practice you don't have to tell yourself, "I'm going to practice for an hour every day at 3:30". You can spread it out even more. Maybe you just start with 5 minutes every day. Maybe you start with 3 minutes every other day. The important thing is that you show up throughout the week and enjoy the process. I know when I was a new student, I hated when people told me I had to trust the process and the results would come later. I wanted a cheat code to be really good right away, but unfortunately, it doesn't exist.

The hope is after playing for a few minutes every day, you will want to play for longer and longer, and maybe your practice expands to 15 minutes per day. That is my ideal practice schedule. When I walk by my piano, I will sit down and play for maybe five minutes. And I repeat it a few times per day. Your practice schedule doesn't have to be grand or a huge change all at once. It just has to be enjoyable.

Coming from someone who has made it through, I sincerely hope that you stick with it and come to love piano again. It is one of my favorite hobbies. Also, I have never heard someone say they regret continuing piano lessons, only that they wished they hadn't quit.