Dear Bryce 10234,
Thank you so very much for bringing your deeply personal confusion here to our forum. As you are already starting to experience, we are a very supportive community.
We know that the very basis of healthy long-term relationships is mutual trust, and the basis of trust is open, honest, and caring communication. And, the communication is even more important when the trust has been strained.
All that said, our guilt can all to easily cause us to blame our partner when we try to talk about the things that we feel guilty about with them.
We would like to encourage you to consider a few things.
1) Since you find it extremely difficult to talk, you might, when you are alone, call Life Line ate 13 1114, or Beyound Blue at 1300 22 4636, where you can practice talking to the mental health professional. The professional will not get upset by anything you say, and, with your request, can help you learn how to say what you are struggling with trying to say to your partner.
2) After you have practiced talking, Relationships Australia http://relationships.org.au has couples counsellors who can guide both you and your partner through talking to each other, in a safe and healthy way.
Please remember that we are always here to support you.