I think emotional blunting (also known as reduced affect display) as an anxiety symptom appears to be like what you're wanting. However, you may need context to specify the anxiety part. The second link I provided pretty much describes what you described. The first link might look a little scary, though, as it pertains to all kinds of serious conditions. It seems the second link would describe wanting to be able to feel emotion as anxious, although that's pretty broad. We might as well include words such as discontent, frustrated, etc.
However, this appears to be a clinical term, and may not be what you mean. I'm not trying to diagnose a condition or anything, and I'm not a medical professional.
As a person who has often experienced things akin to what you described (e.g. wanting to grieve, but not being able to weep or some such, just feeling non-chalant about most things without particularly wanting to change, wanting to be excited about things people around me are excited about, wanting to laugh at a joke I understand is funny but for some reason I'm unaffected outwardly and it doesn't make me laugh), I have not as yet found a word to describe exactly what you mean. There could be an answer, but this is as close as I've gotten so far. Maybe just wanting to feel alive again is sufficient for what you want.
It seems context would really help the answerers. Apathy would seem to be the context, but in what sense matters. Like, how you want to react.