It sounds like there are several things going on right now, but here are my initial thoughts as I read through your "wall of text" (which is fine by the way.. )
It sounds like you are concerned that things have changed between you. Which they HAVE. You are moving away from her. And she is not coming with you. It also sounds like you probably have a lot of feelings about that, perhaps guilt or just anticipating that you will miss each other. And you want to check in with her, a lot, to be sure she is okay and that there are not issues you should be addressing with her, etc.
It also seems to me like she does NOT want to be talking about it all the time. Every time you "check in" with her, she is reminded of what is going to happen. She may resent the feeling that she needs to be checked in with in the first place.
Can you go for a while without checking in about this? Can you not bring it up for a week or two? Ask her if all this attempt to communicate is just NOT what she is actually needing? Sometimes there can be too much communication, talking things to death. I have been in relationships where people just wanted to "process" what was happening ALL THE TIME and it was difficult for me. Once I am done processing, I kinda dont want to talk about it anymore. It's done.
So, my communication advice would be to back off a little for now. I know that your need to communicate with her may feel high to you right now, but it may be more than she really needs. I suspect this is more about your desire to "make it right" with her, and not feel so bad about leaving her? Maybe letting her set the pace on that would be helpful and allow her to feel like she has some control over the communication. If you are not leaving for another year, there is plenty of time to talk about things.
Hope that helps.