Pimple/boil on penis shaft

HI im desperately looking for some advice on a pimple on my penis that occurs in different areas at random times throughout the year starting a year ago, i can supply pics if needed but its currently painful, pain subsides and leaves a ugly scar if i hack at it, which i have avoid doing this time to avoid leaving a "scar"

Sorry, i forgot to mention that i am currently applying Bactroban to try dela with the problem, thanks.

Hi Grant, sounds really painful poor you! Have you had a doctor take a look? Have you also had a full std screen? 

No @joanne i have not due to the fact im a bit embarrassed and i want to be sure im not over reacting over just a common pimple and hoping someone qualified enough can look at it 

No @joanne i have not due to the fact im a bit embarrassed and i want to be sure im not over reacting over just a common pimple and hoping someone qualified enough can look at it