why don't I feel?

[brioche]

A fairly common thing that happens during psych treatment is a period when you feel like you're behind a mask and you're just observing life. I thought it was known as the imposter phenomenon, but that's another kettle of fish entirely.
You basically put on an act, and aren't actually feeling anything.
I think it's a protective response in a effort to deal with the changes you're starting to feel. But it still needs to be dealt with. It won't just go away without a conscious effort.