Hyper sexuality is a condition in which people engage in sex physically or think about sex through fantasies to the point of distress and discomfort. There is a possibility that you are in the grip of this condition. I am of the opinion that you need to handle this with the help of a psychologist, to begin with. Engaging into more of social and familial interactions, reduction in (and gradual elimination of) watching pornography etc. could help you. Many in hyper-sexuality condition are introverts who spend a lot of time alone, fantacising. If it is so in your case, widening your social interactions and engaging in meaningful hobbies might help you. Having a stable sexual partner with whom you can interact without inhibitions, guilt and fear may also help you. In any case, you may discuss all these with the psychologist when you meet one. He / she may even suggest you see a physician / doctor.
Your pain in testicles could be 'Blue Balls' which is known to be a condition that occurs when one gets sexually aroused for an extended period of time but does not have an ejaculation.
Next Steps
Please consult a psychologist.