Hi, agree with all said about practicing hills, the more you do, the easier they get. Technique plays a big part... many try to wrestle their bikes up the hill to poor effect, whereas a nice relaxed approach will pay dividends. My big tip here is prior to the climb, get comfy, sit back on the saddle, AND RELAX - especially the upper body, arms, hands, neck, every part of your body you don't need to propel you forward... then find the right gear and then gently wind yourself up, find a nice rhythmn... oh, and RELAX... did I mention that?
It's also good to learn to climb 'out of the saddle' or 'Honking' as it allows other muscles to share some work and gives extra short-term power, again, relax...
I also as mentioned tend to look at the road just in front of me and try to think of something that's not cycling and before you know it, you'll be at the top (or in a ditch
). Much about climbing is all in the mind!
Box Hill is a good hill to practice, nice long even gradients with bends to mark progress. I used to haul up it on a 42 x 15 fixed so your 34 x 25 should be a peach after some practice