THIS IS SO ANNOYING

Lo
Straight to the point, i am 14 years old and I seriously want to use tampons but my mum won't let me😡 Cause she Got the toxic poisoning thing when she was in her 20's but I seriously need to use them due to being a horse rider and very active and sporty person.
Every time I go to a shop she is always behind me and won't let me go out with friends until I'm 15 😩
I've tried getting my sister to talk to her and she failed as my mum wouldn't agree, I've talked to her and she wouldn't agree 😕
I don't know what to do😶