Hello: according to the situation you described, it is thought that it is caused by postoperative scar hyperplasia. After prepuce surgery, the position of the frenulum of glans penis, which is the position you mentioned, is the most prone to edema. It will take half a month to recover, but it will take more than a month.

Guiding opinions:

Generally speaking, scar hyperplasia will slowly soften over time, so don't be too nervous. You can apply iodophor to disinfect your condition, pay attention to hygiene, and it is best to go to the hospital for examination if there is secretion. If you still have this lump for more than three months, you may want to consider reoperation.