It does get easier eventually, but you have to work at it, I'm afraid.
When I first started commuting to work, my climb started at the 1 mile mark, had a long slow climb for 2.5 miles and then climbed hard twice to the end. On the first few commutes I could not even make it to the top of the first climb, but a week or two in and it was only the 2nd climb that defeated me. It took a while, but I actually came to find the 2nd of the two climbs easier. Apparently the climb is only 200 feet in total, but it used to feel momumental to me in those early days. Going home on the other hand was 10 minutes faster

In the end I actually changed the route to be longer and have much more climbing in it - taking it to 375 feet of climbing...
Now, I look back and wonder what the problem was!
It will happen. It takes time, a lot of effort, but it will get much easier the more you do it and that comes from someone who is both (a moderately severe) asthmatic and has high blood pressure.