Daemons haunt us all, choose and calm overcast day with a low pollen count so your hayfever is controlled. Approach the hill, get into your lowest gear and expel them.
When climbing a steep hill I tend to look 2/3 foot ahead and only at the road. I never look to the top of the hill as it never gets any closer. Get out of the saddle and turn the cranks in a controlled and calm manner. You WILL get up and once there you will be thinking – what was that all about.