I enjoy sex very much but where i am willing, my body is not. When i have sex too much my balls become really small. Is there any diet, or something that i can do to increase the amount of sperm I produce?
By the way... I am almost out of the eros lube that you suggested, looks like I'm gonna need more.

Why are you worried about your balls getting small? That has nothing to do with how much sperm your body produces. Your balls stretch out and elongate when you are hot - and they get small and close to your body when they are cold. During sex your body get hots - after sex is over your body cools down.

Well next time you buy lube - buy 2 or buy a bigger bottle!

Sperm is manufactured in your testicles, but stored in your seminal vesicles where it is mixed with other fluids, then travels to your prostate, mixed more and then expelled out.
If you are worried about semen quantity, and your are thinking larger balls produce more fluid, which is questionable, simply try drinking more water. Certain meds you take might lessen the amount...like anti-histamines etc.
Just a note: For anybody this concerns...smoking, drinking can also affect performance. General health is a good thing to control for a happy sex life.
Gregorio