put your thumbs in front on climbs. your body will follow, as you do your pedal strokes, into a more naturally balanced position and allow you to use a smaller gear than you are using that causes you to run out of "legs". this will also help you build up more strength, balance and confidence.
let some air out of your back tire if you are running high psi,the lower the better.
if you dont make it, go back and try it again while its still fresh in your mind but dont have a "I cant do this" attitude or you will prove yourself right.