NoFap gives me Blue Balls or Sore Balls?

This is quite normal, especially in the first few weeks of recovery or whenever you facilitate arousal unnecessarily or involuntarily at times. You will get testicular congestion, where seminal vessels get engorged with blood or semen at times, like the penis, but this usually subsides of its own accord. Masturbation is an easy fix, of course, and a doctor might suggest it to a non-addict. Masturbation isn't the only fix, however. Again, such pain is not permanent, and it comes and goes, and the testicles naturally release semen in many other ways besides MO or sex, e.g., through the inner body itself, with wet dreams (remembered or not), urination, precum episodes, etc. Tylenol or aspirin might help congestion too by thinning the blood vessels a little (take as prescribed). Cold showers on this area can help reduce/subside pain (but I've never liked cold showers myself/not direct enough), and I've even found an ice pack helpful - but not ice applied directly to the skin (don't want skin burn), but buffered through a cloth of some sort (use a medical ice bag or a ziplock baggy covered by a cloth). Some men (by doctor's advice) actually use ice on the groin area to increase fertility, by cooling an overly heated scrotum so as to prevent a low sperm count, or they use ice for a groin injury. This, however, is not our reason for the ice, which is to reduce the feelings of swelling and discomfort, helping you through the urge to PMO. Sometimes this is particularly helpful when trying to sleep. The slow penetrating coolness helps reduce the pain and discomfort. If you try it, let me know how it goes.

Of course, if the pain becomes clinically acute or sharply painful and abnormally prolonged over days, a doctor's advice might be warranted. I'm speaking above of those usual short, repeated pulsing rising spikes, followed often by low-grade continued throbbing even. The later is expected and normal in male biology even.