If you do this route at least 4-5 times per week, for the next 1-2 months you will improve.

And it helps that there are some cooler days to do this to become better.

Just don't hyperventilate, but breathe in smoothly, abit deeper, when going up the hills, try to relax your mind while remain focused and strong.

And you will get to a point, you will want these same/similar hills in a daily ride..for fitness.
You're gonna feel like a goddess soon.