I have a long climb on both ends of my commute. When I first started I struggled to finish the climb. Over time it got easier, and I got faster.

One tip I got was for longer climbs make sure you are keeping a good cadence. If you start pushing really hard and peddling slow your likely to start walking sooner then if you can keep your cadence up.

I am sure a lot of people could give you better advice, but try different gears/cadence and see if it helps.