Hi,
i got exaclty the same thing you explained above ! (welcome to the club hehe)
yeah it felt like very tight and difficult but got okay afterwars.
I suppose it got irritated because of the mouvements while having sex.
Anyway, now I am 5 days after the red mark things and it is now completely gone and it is not hypersensitive anymore. What I did was (the day after I think) is putting some creme/lotion for irritations and burnings (once, before going to bed) and left my penis head naked for a few minutes.
I did not masturbate during all this, I didn't want to get it worse. Now everything is ok again and erections/urinating are not painful anymore.
I hope it will get okay like it did with me.
Good luck