Hi Thank you for asking HCM I have gone through your query.Semen will be diluted when you excessively masterbated everyday.That is usual.But if it is diluted even after abstain from that for some days then a semen analysis can be taken to rule out any problem.For premature ejaculation you can try following methods.You can do squeeze and stop technique.You can deviate your thought to something nonsexual when you about to near ejaculation.You can put on a condom or condom with anesthetic which will decrease the excessive stimulation on penis and there by prevent premature ejaculation.If all these not helping then you can approach an Urologist or sex therapist or Psychiatrist for behavioral therapy and medicinal management like antidepressants.Hope this may help you. Let me know if you have any further query.