talking about treatment is very premature. you need to first be medically evaluated and diagnosed to determine if there is a problem and if so what would be the cause. it would not be possible to blindly do this over the internet without any medical history (i don't even know your age) so seeing a urologist would be an appropriate step.
why testicles shrink to smaller size and also penis becomes smaller in size? . quantity of seminal discharge also decreased. is there any role of testosterone in this case? what should be the treatment?