I suffer from emotional numbing, too. I've only noticed it recently, but looking back it's been there ever since I became more stable post-trauma (at the end of my time being traumatized, and for a short time after, I was in a state of psychosis). It hasn't even been two months since the end of my years of trauma. I still feel negative emotions strongly, but I feel numbed to positive ones. I also have noticed that I feel numbed to things that would usually make me cry. At a support group meeting I was at tonight, there was a girl who was suffering from a condition that could kill her very soon. She had already clinically died and been resuscitated multiple times in the previous year. She told her story and I felt no emotional stirring. Hearing things like that used to make me want to cry. I haven't even cried in at least a month, if not longer, which is unusual for me.
I also feel really uninterested in activities that I loved doing, and just uninterested in everything in general. I often sit around not knowing what to do and not being able to decide on anything because everything just seems boring.