Help with frizzy hair

My hair is wavy and is abt 2-3 metres from my shoulders whenever I let my hair down after 5 mins it turns into a mess so everywhere I go I have to wear a ponytail which sucks please help!

ok, I used to have this same problem when I was in highschool, I would actually go to school early and bring my flat iron. lol, but if you dont want to blow dry it or flat iron it, the best thing to do is use product, when you get out of the shower put a light mouse, and anti frizz cream in it, then when hair is dry put the anti frizz in again, do not use gels, and hair spray with alcohol also frizzes out hair, but I still use it, just get a light hair spray : )