After feeling as though my already-small breasts had gotten flatter, I've decided to measure myself to find that I am less than the size I measured myself at previously, which was 34.5" inches approximately. This is very depressing since having breasts was the most fundamental part of my transition and that I am already nowhere where i want to be in my transition. This sets me so far back.   

Breast size naturally fluctuates.  This is especially true if you've lot weight.  So unless you lost several inches while maintaining the same weight this is normal.

If you are losing weight, or do an exercise that collides with your breasts it is obvious that they will look more flat, although its weird,

Although if you feel that now, means you didn't have very pronounced breasts to say, how much do you are with hormone therapy? because if you take less than 1 year it makes sense too.

I've been taking hormones since April 2014!

I'm still at an AA cup. Not being able to get past that size already drives me dangerously insane.