Aww.. I'm so sorry this happened to you OP :( You have every right to feel angry.
Sadly, competitive sport remains, in some clubs, very bullying. My DD's are swimmers and the coach shouts, swears, humiliates and puts the swimmers he dislikes, down a lot. Often coach makes the kids cry (though they are then blamed for not being 'tough' and mocked for crying). We will be leaving the club soon due to this. The club finds it hard to retain swimmers or recruit new ones (and wonders why!?) Ellesmere college has recently been under fire for bullying.
I think that because of attitudes such as 'that's how it's always been' and bullying disguised as 'building resilience and character', bullying and abusive behaviours continue in sport. Parents seeing winning at all costs as more important than their children's wellbeing also adds to the problem, as does the complete apathy of any sporting body to do anything about it.
Welfare officers at youth sports clubs are often just parents who buy into the bullying programme, so are not of much use.
To change these cultures there needs to be proper monitoring of clubs, accountability, and children and young people need to know they can report stuff, who to report to, and that they'll be listened to (not picked on more). If a teacher treated kids the way many sports coaches do, they'd be struck off. We need that same culture of zero tolerance for mistreating kids, to be instilled in sports.