I never ignore any letter. Please always trust people.
It is possible that she is facing some problem at home & she does not trust you to tell. Why her mood is like this?
You just keep yourself away for some days & keep silent.
But pray to Allah for the goodness come to both of you.
Friendship needs to sacrifice for each other.
If we can not then we loose our friends.
Try to look at her good qualities .
Still if you can not walk along. The doors of going away are always open.
To break up is easy but to join is difficult .