Methinks you're on a semi-poor fit.

Try rotating your handlebars/hoods upwards to bring the hoods upwards OR rotate them downwards to bring the drops closer to you.
I really doubt flipping the stem to a negative rise [is this what you are asking us?] would make you feel MORE comfortable.

Ultimately, puddin' said it right. It may be fit or your fitness.
Just because someone is 135 lbs and 5'9 doesn't make them Superman on a bike. There's plenty more to that.

Good Luck!
-Peter