My emotions have been very wacky - can't say I've been emotionally flat overall.
However, my emotions tend to run wild over small, unimportant things. When it comes to things that actually do matter and should concern me, I simply don't care. There's a definite "emotional flatness" that occurs.
For example, I might cry for hours over the tone of your voice when all you did was give me a simple, innocent, "Hi, how are you?".
On the other hand, if you walked up to me and told me you hated me and all the reasons why, chances are that it simply wouldn't register. I wouldn't feel anything positive or negative about it. It might suddenly register several days later, but often I can talk about big issues in life and why they're matters of concern without actually feeling anything about them.
This is slowly normalizing, but it's been an interesting life!