I believe I have something similar, but its rather small and I’m not even sure if its still there anymore. I think it was just improper jelq technique (jelqing when I was close to 100%) that did it, but it was a small veiny knot just below my penis head and though it was not painful, it did have a momentary sting when I’d do certain PE workouts. I don’t believe its there since I last did PE but I will check again. I’m not too concerned personally, I think giving your penis some off-time, and softly massaging it in the shower can help (I’m no doctor so don’t take this as professional advice!!).