Re: Sperm discharge in urine
Pus is generated by the immune system fighting an infection. It's usually white or off white stuff like mucous (it does look a bit like semen but it's totally different).
Because you seem to have kidney stones, you should see a doctor for ultrasound exam to make sure they're not going to kill you or anything (not likely but worth knowing!). And you can get antibiotics and/or antifungals for the infection at the same time.
If you have an infection (to have pus), avoid milk and cream until you've recovered. Those make it more difficult to overcome infection. Calcium and phosphate (both high in milk) cause most kidney stones too.