For just once I'd like a helpful answer on here :'( no matter WHAT I do I cannot straighten or curl my hair?

Everytime I straighten it it takes like 2 hours just for it to look SEMI straight and it always has this ugly little wave to it right in the middle of my hair :'( and curling is even worse, forget that, the only times I've ever been able to curl my hair they ended up making me look like shirley temple, I hold the iron on there for 10 minutes sometimes and nothing! HELP PLEASE!!!!!!!