Very few people can resist your sustained intention to love and accept them exactly as they are, and your daughter is not likely to be one of those people. In the mean time, though, there could be any number of things going on. She could be angry with you about the changes in that last six months. She could be angry about the big portion of her life away from you and trying very hard not to love you because you might go away again (never mind if you didn’t go away/wasn’t your fault/couldn’t help it, she’s two.) She could be upset about the changes in you which you find to be all positive – and no doubt they are but some kids prefer the devil they know. She could be going through a phase having to do with attachment to her mother and having nothing to do with you at all. Or any combination of the above plus whatever else she has thought up.
Try not to be too reactive to the “you’re sad” thing. While kids are eerily observant my own experience is that they are mostly observant of what gets a reaction out of their parents and it sounds like she hit a bulls eye with that one. I wonder how your wife responded to that?
In general, try to find something that you always do with her. Make somethign up if necessary. It does nto have to be a big circus like thing, it does need to be a consistent, every single day come hell or high water thing. She needs to see you stop doing other things you consider important to do it.
We had a not dissimilar situation with both of my kids when Dearly Beloved became more involved with the family after some years of having had the kinds of jobs which routinely pull long hours. For Eldest, the thing that helped was that his father did his reading homework with him – this was easy to sell as the reading homework was in Dearly Beloved’s native language and not in mine.
But the tale of Youngest may be instructive, as Youngest was most vocal about rejecting his father’s new presence in the family. He did all you mention and more. For Youngest the magic key was when his father took the job of taking him to the toilet in the middle of the night every night. (Youngest slept right through wetting the bed and never noticed until the next day). This was not done on purpose, it only worked out that way because Dearly Beloved goes to bed later than I do.
This last was most puzzling to Dearly Beloved since as far as he could tell, Youngest remained unconscious throughout, or nearly so. (That was after all the problem) So it was not as though they were having Quality Time together or anything. Doesn’t matter, he did it every night, night after night. When he was tired and didn’t feel like it and when his back hurt and when Youngest didn’t wake up and when Youngest was mad and yelled at him and when Youngest was happy and sang a little song.
Don’t take it personally. She does love you and does not want to show it/fears it for some reason known to no one, not even her. She has to feel safe and there are few things more vulnerable than a 2 year old. Find something regular, routine, low stress and do it with her every single time. Over her objections if necessary, she needs to know you love her even if she’s a little jerk. If you do something just for her, tell her that – I am glad you like it, I thought of it just because I thought you might like it. You can let her know that she hurts your feelings or what have you, if you can do it without being manipulative or scaring her. Uniform positive-ness gets a little creepy and some kids do have great radar for when you are faking it.
You are just going to have to feel your way, try to remember it will be over before she gets married (as my great aunt used to say)