I'm very much the same. I start with the big picture, but what often happens is that I do more planning than I do writing. The story is always much bigger and better in my head and I can only sustain so much attention on writing scene-by-scene; it becomes an inner battle between what I've put down on paper (mechanics and expression) and my own free-reign creativity. On the other hand, if I give myself too much free reign, I get frustrated when I write myself into a corner or don't know where to go next. It's an awkward balancing act. Or additionally, if I've already feel like I've "told" the entire story in my head, I lose interest in putting it down on paper. It's a complicated process for me.
Where emotions are concerned, they don't come naturally for me either. I actually make a list of things that someone might be feeling in a situation and match it up with body-language that would an expression of these feelings. I take a similar inventory for visual and auditory information. Maybe this is a technique that might work for you too?
I've read your poetry before and I remember liking it very much. There's a palpable rhythm and structure to your verses that comes off as very natural and smooth.
I really do hope you will give prose a chance. I would love to see this abstract poem you're working on too.
Cheers!