Love is not jealous. Yeah, it normal that we tend to feel that way a bit here and there, we are human. But if its to the point where its extreme, it shouldnt even go there. Now thats just being controlling! Love is patient. Love is Kind and does not hold any record of wrongs.
I think its best if you just tell her that you have been very busy with work. Say that you have been doing alot of things that need to catch up. She has to respect in what you tell her. If she has an issue about that, just say, "Im sorry that you feel that way, but I have to do what I have to do."