Need to Strong my sperms for child birth

Patient: I am 19 at feb. 2015 now i am going to 20 at feb. 2015.I had done many time hand practice enjoy it but now i realize that it will cause a danger for me to have a child in future but I’m thinking that i had lost all my good sperms and now only yellow and little amount came out.I want to know that is there any cure for this problem that i will have a child in future ?how can i check my sperms are fine for future then i will stop doing hand practice?

Symptoms: Threat about weakness of sperms

Doctor: