Want to be better at communicating

My girlfriend and I have been trying to communicate better, but always seem to hit some sort of mental roadblock for no apparent reason. She doesn’t want to talk about some aspects of her past, for instance, and I don’t like speaking about my family or friends. We don’t think this is a problem, but I sometimes wonder if this hesitance on both our parts is a sign that we aren’t as comfortable with each other as we should be. I want to be more open but refuse to do that until I feel she is being equally honest with me about everything. How do we become better at speaking about difficult subjects? We love each other a lot and want to take this relationship forward.
To love each other and want to be together is great, because it sets the foundation for how this relationship will evolve. You can’t force communication or intimacy, and the first thing to do is be vulnerable instead of stubborn. To withhold parts of yourself in retaliation is childish, because it gets in the way of better communication. There is no rule that says you should both be comfortable enough with each other at the same time. What you both choose to share about your personal lives is entirely your prerogative, and you will both feel like sharing what you choose to in your own time. There is no need to try and rush the process. All you have to do is focus on how comfortable you are and talk about anything you feel like talking about. Give her time and space to feel the same way.

Should I tell my friend that I am falling in love with her? I am afraid she may make fun of me, which is why I haven’t been able to say this for almost a year.
You won’t know until you say it. And a friend who belittles you for being honest about how you feel is probably not a real friend to begin with.