200 things non-equestrian don't understand

I want to Quit riding...

Why? Its not that I don't like riding, its because of something else. I love to ride, and Almost all i've been talking about to my parents is how exciting I am when we can finally move and get our own horse. Right now, I want to quit riding and horses and the future I want to have with them. It because of my parents. The way they are using it is like a punishment. If I fail one class, no more lessons at  all until I get an A on it.  I miss two or more classes and get really upset about it, and all my dad says  that I have to get used to change and not to get upset about missing  lessons. Multiple threats that my lessons will be canceled for good if I don't get my grades up.  Its "a reward" for doing good in school. But over the summer it was  a reward for babysitting. Its supposed to just be a reward for doing something, to them, not just something I like to do  just because I want to. Even today I was talking about how it was so exciting that on Monday I got to jump, and that next lesson(which isn't until January 8th) I'm going to ask if I can learn to canter, and all I got was " If you get tp go to your lesson.We'll have tp see if your grades are improved." I don't think they even care if I ride or not. They know I love it, and they used to ride too. They had horses and my mom used to barrel race, even though she never entered any competitions.  I have a week to get my grade in a class from an F to at least a B, but they expect an A. Maybe they think if they make me quit riding it will motivate me more?  If they do care, they dont show it at all. I do TaeKwonDoe also, and they aren't going to let me quit that even though I've asked to, yet they are trying to make me quit riding? If  they do make me quit, at this point, I'll gladly quit.I had to stop going to another lesson that was being changed to Tuesdays instead of Fridays only because Iwould have to go to my lesson,  then as soon as the lesson wqas over and the horses were up, I would have to go to Taekwon doe, and wpould probably miss first cxlass, even though we go to firstv and second class, and could easily skip first class and just go to second..Any advice? Please be honest on what you think.