You said that you got engaged and are now far from your fiance, questioning your feelings about him. It's perfectly normal to feel the way you do.
If I was in your situation I would also feel lost and agitated.
Did you know him before you got engaged? Are you close emotionally? Are you doing this because of obligation to your family?
Sorry to ask such questions, but it doesn't sound like there's anything wrong with you medically. In the US we are quick to prescribe pills for everything, and this is plain wrong.
Sometimes just to feel our feelings seems like an incredible task, but it is not impossible.
I'm sure that in time you will find your way.
Best wishes,
Daniel