Does this happened suddenly or over the time?
I had one day a sudden reduction of sperm about 20 times less, just a few droplets. Then in just 6 months the time to ejaculate started to shorten until today if I do not take any medication I ejaculate immediately, this could be because I am not getting such a hard erection.
Currently I am suspecting that I have some form of sperm leakage. I suspect that during the day sperm is constantly leakage due to a damage to the so 'valve' that lets sperm out. If this is the case than it can even explain the decreased sexual interest and feeling very fatigued after ejaculating.
Although there sure are supplements which can help with such problem, I do not know if there is some kind of operation for such problem.
how old are you?
have your dr draw blood testing your FSH. FSH is a signal from your pituitary telling your testicles to produce sperm.