It's kind of a crude term, so my answer here will be kind of crude, haha. I hope that's okay.
Ever heard a guy say, after seeing something like a video of somebody climbing a tall tower or something, that they felt fear? And that they felt it in their testicles?
basically means that.
here is a kanji-fied shortening of , a colloquialism for (testicles). is a sort of sound effect -- like something whizzing past you. To be honest, I'm not entirely sure how the comes into effect here, but... it makes for something that's kind of fun to say, haha.
Basically what she's saying here is "[I got so scared that] I felt it in my balls, and I'm a woman!"