Sad and Bitter

Feeling a combination between bitter and sad. I am leaving the elementary school I've worked at for a year and a half. In that whole time I have been a sub. Yes, you can be a substitute for a year and a half, who knew. The child that I was an IA (Instructional Assistant) for is going to another school into a smaller Special classroom. I will be at the new school for a couple of weeks so that she will be able to transition a little better (we hope).
I'm sad because I will miss the kids that I have gotten to know in the last year and a half. Not just my little girl, but all of the kids.
Bitter, because I don't understand why I am not hired by the school district. It's not like I'm not a good worker. I have never had a bad reference. EVER.
I also know that one of the reasons that she is going to the other school in a Special classroom is because it is cheaper than having a one on one aid. It may end up being really good for her, I don't know. But I do know that it was a monetary decision on the part of the school district. She was making progress in our classroom, she has friends there that she is going to miss and that are going to miss her, and that also makes me sad.
Love to you all.