When I was grooming Saddlebreds, I saw teenage Equitation riders come in from their class, grab their full length mink coats and toss them on ground because they didn't place well. They had 100K horses and up, at 10 through 18.
Didn't resent them a bit, thought they were twits. AND when their trainer got there, or got wind of their shenanigans, knew they were going to get ripped for their attitudes too, she didn't play that at all. And would put them and horses out of barn if it didn't stop.
Always amazed me how people could let kids act like that.
Anyway, as to you. Quit feeling sorry for things you can't fix, at your age, you can progress I am thinking, go to work for succesful trainer in discipline you are interested in, and work up to having a nice horse of your own down the road.
IF you are determined enough, and take advantage of opportunities that you will find, or make? You can be able to purchase a nice horse for yourself one day, either through your name or your expertise in identifying a young prospect that has "it" in him or her.