Flat Irons equal damage?

so my hair isn't straight and it isn't wavy either.its more in between.but my hair is more straight then it is wavy.my hair is also thick and frizzy.so its kinda impossible to go without straightening my hair.i use heat protection.but it gets tiresome to keep having to flat iron my hair everytime i get it wet.so i wanted to get my hair chemically straightened.but my mom wont let me.so what else could i do to my hair?