Swollen meatus and underside

[Tiglemingle]

I am circumcised. I woke up in the middle of the night to urinate and found my meatus swollen and the underside swollen. In the morning how ever the meatus swelling completely subsided but the underside is still a little swollen, though has subsided.

Since then I am frequently urinating. I have no pain or burning or discharge.

When I woke up to urinate, my penis was erect and I found the fabric of shorts was very rough.

I had partially protected oral sex 6 months back, and I also had incredibly frequent urination 14 days after this exposure(may be due to anxeity).
About two months back I had the pubic region just above the penis base swollen for 3 days(size of a quarter) after which it subsided. After the pubic region subsided, 4 days later I developed what the doctors called folliculitis.(If this information is useful in determining what is causing the above).
What could be the reason for the swelling? Could this herpes? or a bacterial UTI? Or just meatus chafing against the rough fabric.