Sorry to disappoint you but, the secret is that there really is no secret other that your own commitment and mindset. However, the good news it that anyone can make improvements as a climber.
Don't fear the climbs
If you are fearful of climbs you need to change your mindset. Hills are tough, professional athletes find hills tough, so you can expect to find them hard also.
Climb hills regularly, see them as your friends that will help you get stronger. If you can tackle the climbs it will also improve your speed on the flat.
Understand the gradients, if you have a bike computer set it so you can see the gradients. Having an awareness of the challenges you are facing can help in your acceptance of having to suffer.
Above all keep climbing hills
If you are have to walk getting up a hill, never see it failure. Motivate yourself to keep practicing that hill until you can get up it.
Look at your improvements over time. It may not be completely linear, but with practice overall you will make improvements.
If you are committed to getting stronger on you bike book a discovery call to talk with us about coaching or coming to ride with us in Mallorca.