26 year old male with no STDs or any other health issues. Masturbated and tightly gripped the base of my penis while doing so. I gripped really hard. Before ejaculation I let go and ejaculated like normal, but felt an odd somewhat dull pressure/pain on the dorsal surface of my penile shaft about 1 inch above the base (traveling in the direction of my penis, i.e. not horizontal/diagonal). At the area of the pain was now a hardened cord with a bit of a bump at the middle of the cord. It is not visible but can be palpated. It seemed like my penis took longer to become flaccid after that. I stopped any masturbation and let it rest for a week. It seemed nearly better but masturbating very gently caused it to return somewhat. I have gone a bit more than a week without masturbation now but want to check that something like this will go away and not be any long term damage. I still feel a dull pain at the area at times when the penis is flaccid. No issues with erections or ejaculation. Is this a lymph or vein issue? Will NSAIDS help or is there anything to help with lymphatic drainage/healing? Have I done long term damage?