Talking about difficult things with Bella

I've experienced something new as a mom lately. The amount of empathy I have for my children, and how much I want to guard their feelings in some ways.
Thursday was Bella's last day of Montessori, and Friday was the end of the year party.... Where I learned that one of Bella's teachers - that she's been with for a year and a half is moving away for a better opportunity. Isabella loves this teacher so much. And when the teacher hugged Bella goodbye on Friday night, she squeezed her tight and said "Bella, you know how much I love you, right?".
The next morning at breakfast I told Bella about her teacher moving away. In true Bella style, there were a lot of "why's?". I've had to break other sad news to her in the past but for some reason, this was really hard. Isabella even said she wanted to move away with her and go to the new school with her teacher.
I had to leave the room because I started crying during our chat.
Later that night I was explaining to Bella the things we would be doing this weekend. One of which was a going away party for my sister in law who is moving to Australia for a couple years for school. Again, in true Bella style, there were a lot of "why's?". And again, I started tearing up, thinking about how much Bella would miss her auntie, and how much her aunt would miss our kids. I know she's got a great connection with my kids and it makes me sad to know that they are going to miss so much of each other in the next few years. My kids are going to grow and change a lot. My kids already have a couple aunts that live so far away.
Anyways.... I sometimes find it pretty difficult to explain things and answer questions.  I'm pretty sure the questions and situations are going to get much tougher!
Maybe if Bella quits asking "why?" all the time - it might get easier! :)