got a rough bj few days ago, kinda head a little red penis head but it become more reddish after that bj, what do you think?
Probably just mild balanitis. Personally, I wouldn't see a doctor about that, but if you do, please let us know what they say.
If it's balanitis, then these links may help:
https://patient.info/health/balanitis-leaflet
https://patient.info/doctor/balanitis-pro  
(written for doctors)
Washing (with water, no soap) daily, and taking a leak and washing after masturbation or sex will probably help, and you could also try Canesten cream or Daktarin cream. Loose fitting cotton underwear may help, and some sites recommend washing underwear with non-biological washing powder or liquid.
i am experiencing the same thing, have you learned anymore?