Hi people

Im 25 years old and in good health but about 3 months ago i realized there was blood in my ejaculation after masturbating, i am not in a relationship and haven't been in one sexually, but as time went on the blood became more and more evident to the point were my whole ejaculation is brown, i took a blow to the testicles during football but it has been 3 months and i am really worried, and i get a burning feeling beneath my penis when i ejaculate as well as a tingle on my tip.
I have been to my doctor a month ago and he checked my penis and testicles and found nothing significant and told me it takes time to heal.

Help me out please guys, what should i do and has anybody experienced anything like this because i am seriously worried now!

Thanks