Hi Emilie!
I feel for you and understand the problems of growing up curly in a straight haired world - especially cheering! I would suggest a keratin treatment to start. The effects won't be as permanent as Japanese straightening. Check out your area for keratin treatments that last 3 -6 months. I personally would avoid Ulta if you have one in your area, as I think the treatments are much weaker than other hair salons. You will probably want a keratin treatment that will stay in your hair for at least 48 hours before washing. One of my daughters had the Global Keratin smoothing treatments at a salon and loved the results. You mention sweating, and this will wear out the keratin faster than normal. Although my younger daughter wears a hockey helmet and sweats a great deal in games, but the keratin still manages to stay in for a fair amount of time to keep her happy. She's only had one at home keratin treatment, but it worked really well on her thick 2C/3A curls. Sometimes with curlier hair, you have to have more than one treatment to get the results that you like. Good luck - any other questions, just ask!
3B dark brown shoulder length
Co-wash, Living Proof No frizz, Biolage Gel, Giovanni vitapro fusion leave in