Tough situation now that there's a rift. I would say a phone call was in order to try & talk this out, otherwise it will just drag on & on, which is, obviously, not what you want.
BTW - before you make the phone call, jot everything down that you want to say.
Stay calm, let your mom get her feelings out & somehow tell her, "I can understand where you're coming from & I'm sorry I made you feel that way. I didn't mean to hurt you at all. Maybe I was wrong in what I said & maybe it came across the wrong way. I hope you can accept my apology & we can move past this as I still love you both & don't want our relationship to suffer."
Even if you don't feel you did anything wrong, sometimes it's best to take the high road & be humble.
Pretty much exactly what I was going to offer in the way of advice.
OP, I know from experience that email is one of the worst ways
to communicate when it comes to trying to get honest emotions
and feelings across.
Note I said "emotions...feelings".
The written word can come across in so many different ways!
You tried to be honest, but your mom took it in a way that you
are saying you did not intend.
Try to mend your relationship now, before the move,
and before it grows into more months.
Having a loving relationship with your parents,
especially since they are moving to be closer to you
(if I understood you correctly),
should be a priority in your life.
