Top answer from @judenonesuch. Climbing ability is a lot more in the head that one might think. In your case it seems to be more a question of mentality and technique than a fitness issue to train on.
When tackling a climb, push a little harder to start with, to keep your momentum, then gear down to maintain a good cadence. Concentrate on your breathing too, it really helps to relax on longer climbs.
Top answer from @judenonesuch. Climbing ability is a lot more in the head that one might think. In your case it seems to be more a question of mentality and technique than a fitness issue to train on.
When tackling a climb, push a little harder to start with, to keep your momentum, then gear down to maintain a good cadence. Concentrate on your breathing too, it really helps to relax on longer climbs.