Changed Sexual Partners, Had Unprotected Sex. What Are Red And White Patches On Foreskin?

Hi, I have recently changed sexual partners in the past few days (3 Partners in total over the past week) and I have been having unprotected sex, I recently noticed pain during intercourse and afterwards under the foreskin the skin was white & red & quite blotchy, possible small bumps but not completely able to see as it is recent ( always had small bumps were previously told they were fairly natural to do with glands) Also with the pain I thought could be to do with the fact I previously have had a small tear in my frenulum, any advice? Going to the GUM clinic about this tomorrow but a heads up on any possibilities could be nice, thank you.