What should i do about my frizzy, unruly hair?

I have shoulder length curly hair ( i just got a trim & layers yesterday ) and i also have front bangs. i cannot blow dry my hair or it will be an afro. my hair comes out really nice and frizz-free when i let it air dry (approx. 2 hours) but im going to start working next week from 10-4 and i wont have time to let it air dry. would a diffuser be a good investment? how much are they usually and what's the best one for the $$? thanks