How to convince my mom to let me wear tampons?

I'm 14 and I'll be a freshman (9th grade) in August. I've had my period for about a year. She won't let me wear tampons. I HATE pads. They're so uncomfortable. I hate feeling the blood gush out. I hate sitting in blood. I feel like I have a diaper on. I hate blood period. It grosses me out. Pads are just really messy and I wanna use tampons. Plus I wanna play sports. When I cheered last season it was so uncomfortable. How do I convince her? And what kind of tampons are best for beginners? And you change them like every 4 hours right? Please help!!