It doesn't sound crazy to me...

I've had that happen, quite frequently actually. Mostly when I'm stressed or depressed or when I used to SI (which I've not done in a while now).

It's a form of dissociation I think... like derealization or depersonalization.

link to info on derealization and depersonalization

I'm no medical professional, but that's what it sounds like to me and it's how it was explained to me. Anyone you can talk to? Do you have a therapist?