Talking to your partner about sex shouldnt be a scary ordeal, its a great way to express your wants and needs. Im not sure if theres a specific reason why shes afraid of hurting you but here is a few suggestions.
1. Do ur best to suck it up and talk to her, it wont seem so scary once you spit it out and im sure she will appreciate you telling her.
2. This i have tried in my own relationship, if there are things you want your partner to do and dont know how to express it, try watching a previously decided on Porn that you can watch together. when they are doing things you want to try or think you would like, mention it and do it while watching it, that way instead of sitting someone down having an awkward conversation, it feels more fun and not so pressured.
Also, there is a great Book I read, its called Secrets of the sexually satisfied women its written by two female doctors and it touches base with a lot of different ways to communicate to your partner about sex, i read it a few years ago and it was a really awesome help.