It's your body, so it's your call what you want to do with it. Ignore your parents, because they don't really seem to care for your best interest. My father used to play football in school, but he left because he was having repetitive knee and ankle problems which weren't healing, and even 30 years later still give him some trouble. Luckily for him, his parents were on his side, but the coaches still gave him stuff for "giving up". Just ignore them, you seem to know what's best for you so go with what you are feeling.