I know! It's horrible at first.
BUT the more you tell, the more clinical it will become, the more you'll realize this is what happened TO you... not because of you, not because of anything you did... but that it happened to you and there's nothing for you to be ashamed about because you did nothing wrong. He did something wrong. He's f*cked up. Not you. Your reactions are very NORMAL right now. Believe it or not, you're right on track for any woman who's gone through this. Talking through it, even forensically, will help keep you going on track.
Let's think about when you cut. When you do, you bleed and it hurts. But then endorphins are released and your body immediately starts trying to heal itself. People cut because they want that surge of healing that feels good for a moment while the body is trying to heal a wound.
Your mind is trying to heal but it's not as automatic and instinctual as your body's response to physical injury. This is why we have rape counseling. It's designed to attend to your specific needs from this trauma to help heal the wound. The more you continue with this proper path, the better you will feel.
To give you an idea, I'm still messed up from my ex-husband. He was abusive and he raped me. He even tried to kill our oldest child and me. I have anxiety attacks related to my ex-husband but it's not over the rape or abuse. It's all related to legal crap and my kids having visitation with that freak. I've got scars (both physically and mentally) from what he did to me but the actual trauma doesn't live with me anymore. It's part of my story. I can tell people and it doesn't hurt me to tell people. It doesn't mean my ex-husband is forgiven for what he did. But it means I have healed.
Everyone's different, though. You might heal faster than me.
As far as Stefan is concerned... I know you made promises and that you've broken them now; but, this is an extraordinary time and you are struggling to heal from a deep wound. He doesn't want you to be hurt - and he's right to not want you to be hurt in any way - but I think you will see that his love includes forgiveness.
(That was a long comment. I should've brought a soapbox.)