Hello, The fact that you are getting a good erection is indicative that you have not harmed yourself. Using external device around the cock and balls may cause strangulation, poor circulation and permanent damage that may lead to penile cancer. Do not do such adventurous activities. Recurrent use of rubber bands is likely to cause penile strangulation. Penile strangulation is a disease which induces edema and pain by causing circulatory failure in the distal part. Penile strangulation by foreign substances, may cause urethrostomy or penile necrosis if the strangulation prolongs. Hard materials such as metal rings and soft material such as rubber bands or threads can be listed as materials used for strangulation, do not use them. Be gentle with yourself. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician