Thanks for your query,based on the facts that you have posted it appears that you have nocturnal emission
It is natural to get nocturnal emission during sleep at the age of adolescence and the weakness that you have is not due to emission but it is mind related and due to anxiety
Following measure will help you to boost up your confidence and to get sound sleep
1) Practice regular exercise for 45 minutes followed by meditation
for 1/2 an hour in the morning.
2) Take high protein diet rich in vegetables and fruits and Vitamin A
3)Take anti oxidants like Almonds 5-6 everyday..
4) Avoid alcohol and smoking
Do not worry this will get resolved of its own without any treatment.