Acne on nose. Bump and scar on my face?

I have this problem from my teen age I'm 27 but I still get a big acne on my nose once in a month which takes 45(app) days to cure by leaving a bump on my nose. Sometimes the size of the acne looks almost a pea but size. Which looks red in colour and turns black when its about to dead and leaves a bump on. Rarely i do get small acne on forehead,cheeks and chin regions. They end up as bumps and looks irregular surface on skin than forming a cavities. I request all the practo Doctor personally to suggest a prevention method rather than curing. I was not able to face people in the office sometimes so kind Suggest me all the possible solutions What do I need to do when I got an acne.?What can I do to stop the growth of an acne ? How can I avoid bump and scar on my face? I need to be treated for acne and also for bumps so I request Doctors to help me out...