Red penis opening. Please help!!!

It has been like this for around 2-3 years it has gotten darker in colour if i can remember. The actual head is sensitive but not painful. There is no pain urinating its just red. I don’t know if its a sti or infection. I don’t want to go to a doctor. I just want help. What is it. Can i take medication. Please help. I have pics in the next post.

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