1. When something good happens, write it down, remember it, treasure it. The next thing that happens will not be as nice.
2. You're doing the right thing in venting your pain here. Don't expect her to share now. If you liked something that happened in Rule 1, don't assume it is fixed or a sign of change. Don't expect her to show feelings she cannot find .. yet. She has things boiling in her she is not comfortable letting out. You probably don't want that to happen at home without a C to help her.
3. Letting stuff out in C is very good for her, unless it always leaves her screaming D. Her good emotions are buried under a life of restrained resentment, guilt, and other feelings held captive by the gatekeeper - Anger. Anger must be released to get to the rest. It is not your job to manage her anger. It is for her, in her own time, hopefully within counseling. Encourage it, don't run from it. Meet it head on with all the DB you can. Validate her pain and share in it. Let her see it is safe to do this with you around or it may never all get out. Her happy place is buried under it all.
4. When you think you can't take the ride any longer, trade with me ... please!