bump at tip of urethra extremely worried

i am 16 years old and just recently about 2-3 weeks ago noticed a small bump but very visible and noticeable on the tip of my penis just inside the urethra and now thereseems to be one on each side of the opening of the urethra it doesnt seem to be painful when i dont touch it or anything but when i touch it or rub i seem to feel maybe a slight pain or that could just be because im extremely worried, but this isnt the only symptom that i have been having i seem to haveto go to the bathroom more frequently and when i am finished i have a dribbling of urine still coming out of my penis for about what seems like a minute or more and my urine looks pretty yellow more than normal and when i look closely it looks like i see little white particles all throughout my urine. i also have been experiencing an itching all throughout the genital area but not really on the shaft or tip of the penis but i just think this is from me in the middle of puberty with hair starting to finally grow in and be noticeable. i also have been seeing little white marks all around the shaft but those have been there for a while like up to a year or more and i think they are jus the normal part of puberty but it is probably cause i have been looking more often and been more worried but it seems to look like there may be a few ones that are kind of big and seem to have a little bump on them unlike the other ones that seem to be flat. i did recieve oral sex once a little over 3 years ago and it did not last long only for about 30 seconds or less and i am just extremely worried hoping its not and st like genital warts or something. i think that this seems to be something wrong with my prostate since i am experiencing many of those symptoms but is it possible to get that at this young of an age and what do you think this could be.