My feelings are hurt...or somthing

It's nearly 2 am, I have a presentation in my class at 10 am that is not completely ready, yet here I sit, my mind unable to focus on anything other than the hurt I am feeling from someone elses words from earlier in the day.
I have been struggling lately with the time I am away from Elianna. Since I first became a mom 8 1/2 years ago, my entire life has focused around my girls. Going back to college is the first thing I have done for myself (and really it's not just for myself in the long run, but for now it does feel that way). I am really not away from her much, I have a class on Tuesday evenings and then on Friday when she doesn't have preschool I have class from 8-2. But this month has had alot going on, First the David Cook concert which I couldn't stop thinking about the girls and asking myself why I was there (I did have fun, the concert was ok, MUCH harder rock and louder than I expected, but being with an old friend was fun). Then there was the volunteering at the food pantry for my one class, then there was the play that Bethanie and I went to, and then this weekend when Bethanie and I went to a Girl Scout indoor campout. Elianna has spent the night with my mom or my sister 2 weekends this month. I feel like all I have been doing is pawning Elianna off every Friday. And it doesn't help that every week when I take her to my aunt's house bright and early on Friday morning that she cries when I leave, telling me "I want you!". It about kills me to have to leave! It also doesn't help that I had to keep her home from preschool on Thursday (she locked both set of keys in the van) yet instead of enjoying our time together, I felt like she was a teenager and we spent the whole day battling with each other. All that to say I have been struggling, not feeling like a good mom, having issues with missing my "baby".
Then today happened. We had a dinner at church. I was up at the counter getting my plate, thoughts of where I was going to sit running through my head. I usually sit by my sister but today her husband came, they sat with some other people and there was no room at their table. Then I hear it, my aunt (the same one who watches Elianna on Fridays) and my sister (who Elianna spent the night with on Friday) talking, their coversation goes something like this...
Aunt: (says something but I am not tuned in to what is being said yet)
Sis: Yea, I don't get it, she has no problem coming to our house even though B (BIL) yells at her the whole time she is there.
I realize they are talking about Elianna, how she cries every time I drop her off at my aunts house. That's when my aunt say....
MAYBE SHE JUST DOESN'T KNOW WHAT TO DO WHEN SOMEONE TREATS HER RIGHT
and my sister chuckles a little and says yea, maybe so.
I glanced up at them while my heart broke into a million very small pieces. I am not sure if their conversation continued after that, if I just tuned out, or if they know I heard them, but I was hurt. I AM HURT.
I am the only one on that side of my family that has ever been a stay at home mom. I was there for my girls 24/7 the first 8 years of Bethanie's life and first almost 4 of Elianna's. I took good care of my sister's girls while she worked full time from the time they were born till I went back to school and I took care of my aunts granddaughter from the time she was 8 months old till she started preschool at almost 4 while her mom finished school and started working a full time job. Now that I am in school, I am away from my girls less than I would be if I worked a full time job like the others, Yet for some reason I am a bad mother. Is DH a wonderful father? no, he acts like a drill sargent at times and he doesn't make spending quality time with them a priority by any means but is he horrible? No! And I have always strived to make it up to them where he falls short.
I am just really hurt by their words and am not sure what to do. Will I be able to take Elianna and drop her off at my aunt's after this? I just really don't know. And I guess if I need someone to keep Elianna over night I will call my mom.