Mmmm ... well, there are a few things you can try.

Fluffing. Try working yourself up several times during the day ... uh ... manually. That can help get you started.

Do what it is that really gets you in the mood. The more excited you stay during the day, the more likely you are to have a climax.

I have heard, but never tried ... I should though ... that a Ziplok bag of petroleum jelly taped around your junk and worn during the day heightens your sensitivity. I'm not sure how that works without leaving a nasty mess though.

Those would help me although I still had a considerable amount of trouble until they found the right AD.