I was recruited to college to row and stopped after 2 years. It was probably the toughest decision I have ever made and it is still tough for me, since I love the sport and I liked being part of the team but I really did not agree with the coach's philosophy and approach and I felt as though he squandered the talent offered to him and mistreated his athletes out of stubbornness and lack of understanding of training science. I was happy to come down and work my ass off every day, but not in such an inefficient manner that directly contradicted the coach's stated goals for the team. In truth he was a manically competitive egotist who convinced himself he was of high moral standing and spent all of his time trying to brainwash his athletes into worshipping the ground he walked on while he didn't actually believe most of what he told us. I had a lot of success on the team and had a good relationship with him, but as soon as I started seeing through him I lost too much respect to continue dedicating my life to him.
It came down to the fact that I was miserable every single day. I could deal with being physically exhausted but I would spend my entire day dreading practice, and when it was over I would start dreading the next day and it wasn't healthy. Very few of the guys on the team still talk to me anymore despite them being some of my closest friends, but that further reinforces my decision since I didn't want to be part of an environment that condones behavior like that. It has definitely been hard though to lose so many friends and feel uncomfortable around people who initially defined my college experience.
While I was still rowing I thought that it was the most important thing ever, which is the only way to get through it, but now that I'm on the outside it's clear that nobody gives a fuck and it's a minuscule fraction of a much larger and more interesting university. If you're not happy doing it and you don't see it leading somewhere positive then by all means quit. Your parents will understand as long as you're leaving for the right reasons and you have something viable to replace it. After all they want you to be happy and successful, and if you know what will lead to that then they've raised you well and will respect your decision