Awesome ride - on a hybrid, with hills! Tough woman!

One specific thing to look at is how you're angling your wrists on the handlebars. The more relaxed & straight they are, the better. I have done centuries and double metrics on hybrids (the double on a nice aluminum mountain bike with skinny tires), and my secret is hand position that my piano & typing teachers would be proud of.

Get a bike that **feels good.** It's very individualized. Test drive all of 'em Welcome to the addiction!