Penis Pain Corona Area

So two months ago i had sex with and old friend. It was unprotected sex and since then been having issues. I went to the doc and had blood test taking and nothing shown up. So for two months i been having weird tingling feelings at the penis head. More like at the corona part. If i get a erection it feels swollen and redness right on the corona area. Its not extremely painful but minor irritation. i have no std and have no clue way having this issue. If its scar tissuing how long it takes to heal. Also if its bruised how long healing take.