When I was younger I always wanted to take gymnastics classes, but my mom never let me. Now let me just say that I'm not complaining at all. I also asked to take dance classes when I was 4 and both my sister and I have been dancing since then. She also let us try plenty of other sports over the years; soccer, tennis, volleyball, horseback riding, and cross country.
I am now 20 and decided to start taking adult gymnastics classes a little over a year ago. I'm an adult, so I pay for my own classes, I drive myself to my classes, and I buy my own leos, but my parents were not supportive at all when I first started taking classes. I found out that the reason was that they thought gymnastics was too dangerous and they were afraid I would get hurt (although why they didn't come to the same conclusion about horseback riding, I have no idea...). For the first few months, they basically ignored me every time I would try to tell them about something exciting I had accomplished in class, and it definitely made me a little sad.
About 3 months into gymnastics, I had a major ankle sprain, and my parents had to come pick me up and take me to the ER. In their minds, that injury just proved to them that they were right to never let me do gym as a kid. I wanted to go back to the gym and condition right away, but they told me I wasn't allowed to take classes anymore. I talked to them every single day about going back to the gym, and I think they finally realized how important it was to me. They have now stopped telling me not to get hurt every time I leave for gym

, and they are happy when I get a new skill.
So the point of this extremely long-winded post is to say two things: that your parents may have a legitimate reason for why they're not supportive, and also that this is your sport and you should be doing it for yourself and no one else. Yes, it is hard when we want support from others and don't get it, but there is definitely something to be said for learning how to push yourself and do things because it makes you proud of yourself, and not because it makes others proud of you.