PLZ HELP. I don't know what is wrong with my penis and it is scaring me to no end

I [30M] have been feeling a thin cord like thing, like a ring, around the middle of my shaft for a month or so now. It is not hard, I can feel it slightly when I'm flaccid but it's more prominent when semi erect. It goes around the entire penis, but is more prominent on the right side.

It's causing irregular blood flow as well, the part below this chord gets harder faster than the rest of the penis. But I am able to attain erections (though this has been hampered by the anxiety because of this condition).

There is also slight pain near the base of the tip.

I went to a urologist and he conducted an ultrasound first and asked me various questions, and ruled out Peyronies. He's asked me to do a Doppler ultrasound which is scheduled for tomorrow. But so far he doesn't know what it is

I wanted to ask if anyone here knows what this could be.

Ver nsfw: https://gifyu.com/image/bNwXP