There is a shampoo conditioner you have use to make your hair easier to curl. I know hair dressers used it before blow drying and curling it. There are many brands. I'm only familiar with the redken brand.
Maybe it is the FATES, telling you that you look better with long, straight hair! Not everyone can rock curly hair, but maybe straight hair is your thing, but you just don't know it, or realize it, wanting to be something else!! Be YOU and make the straight hair work!! I LOVE LONG, STRAIGHT HAIR!!
How long is your hair? If it's really long and thick it's likely the weight pulling your curls down. If your hair is very straight, try using a curl setting spray beforehand and opt for hot rollers. Use mousse immediately when you take the rollers out and find a good weatherproof hairspray. If you have questions, message me.