Night fall per se is not a problem. It is happening because sperm production in your body is normal. It will come out either by sex or masturbation. If you are not doing either of two semen & sperms can leak at night when there's normal nocturnal erections, or during urine, or passing stools, lifting weight, or any other stage which will arouse you. so basically it doesn't mean you have illness or you will become weak. There is no connection between blood & sperms, so loosing sperms will never cause any kind of weakness. If you still fear or have doubts we can do a therapy + medicines which will resolve your problem completely. I hope this answer will help you. If you have any questions you can consult me privately. Tc.