Purplish/red spot on penis rim

[Worrymoretoo]

I have had this purpleish/red spot on my penis rim for maybe about a year now i got this red/purpleish sting after i had anal sex with my ex girlfriend, the pain was instant as i pulled out i didnt think much of it because we had anal sex and we didnt use lube so i thought maybe i had teared the skin since i was going pretty fast, but i had pain there for a couple days. After the pain went a way the redish purple spot started to become smaller and now it isnt painful at all except for everynow and then i kinda feel mild pain/discomfort there. The spot is on the rim of my penis and under it as well also seems like its a vein or something. It be great if i can get some anwsers