Ask the Resident (Sex) Advisor
The Resident Sex Advisor answers sex-related questions from college students
Your girlfriend has some issues concerning trust and intimacy as they relate to her sexuality, so getting her to open up could be a long-term project. Talk to her and find out what she's really concerned about. She may be worried that if she fully expresses herself sexually with you, she will lose your respect or it will ruin your relationship. If so, you need to reassure her that this will not happen, that she can trust you, and that exploring different ways of finding sexual pleasure will bring you closer together. Try to express to her that you will, in fact, love and respect her even more as she fully accepts her sexuality. Communicate as openly as possible about what you both want sexually, and try to create an environment between you where it is safe for you both to bring up your desires and fantasies. Also, let her move at her own speed. If she's not ready to do a 69, see if she'd be willing to sit on your face, for example. Take small steps.
In the meantime, see if she would be open to trying a sex position that is sort of halfway between missionary and doggy. It's called the spoon position. Both of you lay on your sides, with you spooning her from the rear. If she brings up her top leg slightly, you should be able to enter her from behind. This is a very intimate and "cuddly" position and might give her enough body contact and closeness that she'd feel comfortable with it.
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