Hey bro, I've been through more or less exactly what u described and i'll try my best to answer. Have u ever considered that she is genuinely busy? because very rarely this may be the case however it seems she might have lost interest a little bit, i know that's not the answer u wanted sorry, there are some things you can do though.
First i want you to understand, in my opinion, the greatest rule of relationships: the one who cares less, controls the relationship. Think of cat string theory, girls get easily bored of things that are always too invested in them, u say you've been with her for 2 years? perhaps she's maybe got a bit complacent, see women want excitement and adventure they want a challenge, of course this usually applies to the courtship phase but i feel it should also apply to the relationship phase. Don't keep making plans or trying to make plans if she keeps flaking as this shows neediness which is the #1 attraction killer. Just let her do her thing and you do yours mate, go out sarging, see friends, play a sport, learn a new skill do something that makes u happy anything to keep your mind off of this situation. Trust me it'll help sort your head out and make things clear. Treat everything she says and does as a Test. Women test men. It's in their nature, they test us both consciously and subconscious. A test is when a women will say or do something to get a specific reaction from a man and then she can judge what kind of man he is. Also never let a temporary emtional state dictate outcomes, e.g sending hurt messages, moaning etc.. A man should be unresponive in the sense that he stands up to her and other people but never whines or moans about things she does becasue it may well be a test in which case.... u fail.
I've been in ur position and it really sucks and that was before i found the community. So my advise for u is: dont be needy, try to care a little less tere are billions of girls on this planet, she may well be testing you to see how you react and dont let a temporary emtional state dictate outcomes. Hope this helps you if you have any questions then message me.
P.s. I found this video really helpful (in fact all of the men's room videos are excellent) :
Frank kermit- the emotional needs of women and their tests:
https://www.youtube.com/watch?v=ztcrC5wgUUQ