Hello,
Thanks for using healthcaremagic.
Young man, just relax as you are not suffering from any pathological problem. Your concern is generally called, "Dhat Syndrome"(loss of semen/sprems).
Note carefully whatever I am going to explain. Normally after age of 13 or 14 almost all boys enters in to phase of adolescence. In this phase
testosterone secretion increased, beard mustache growth started, hair around genitalia started growing and adolescent boys attracts towards opposite sex and gradually learn masturbation(excitation and ejaculation by sexual thoughts though rubbing penis by own hands).
With this semen production (majority by
prostate and sperms by testis) started. As semen produce daily and it accumulate in prostate.Its production generally cost 1-2 % part of your daily calorie intake,so missing 1 % from your whole day food has nothing to do with weakness you feel.It is just perception of yours.
Your habit of releasing sperms is not bad at all until it's compulsion. As most of the young man like you do masturbation. Frequency of masturbation varied from once in a day to once in a week individually.You should not suppress your desire.If you completely stop doing this, after a storage capacity level exceeds in prostate, semen has to come out in night during sleep or during toilet.
So just understand this physiology of body and correct your psychological belief of sperm loss causes weakness.
Yes your BMI is 18, your weight should be around 65 kg. So try to put on.
Hope I have answered your query, late me know if still any info needed.
Regards, Dr. C. K. Solanki