This is something that you need to have examined by a Urologist, very soon. Stones can cause pain in testes. During the exam, be sure to inform the doctor about any medications you are taking.
Firstly drink more water (and then a little more). Secondly go easy on your tool. Try adding some apple cider vinegar to your water (teaspoon per 12oz) drink at least 2-3 of these a day. Also, just because it's so good at regulating all the microbes going on from your gut to your exits add more garlic to your diet. If you are passing stones then you might be tearing tiny fissures in your urethra and letting in other potential issues. Garlic will help neutralize this naturally. By the way I've had kidney stones (to the point of bleeding) and I've tried all this. If you do it for a week straight (faithfully) you should see some improvements. Please keep us posted on your results!!