I have very hard spots under my nipple for about 1.5 years now. They hurt when I touch them or squeeze them. It also causes my breast to be kind of large, which is really embarrassing. Will these go away?
When a boy is growing, the changing hormones can cause an adolescent nodule. This is a small, hard lump directly under the nipple that is tender to the touch. These require no treatment and typically disappear in about a year. The National Institute of Health, a U.S. government agency, notes: "Teenage boys may develop breast enlargement and lumps because of hormonal changes in mid-puberty. Although this may distress the teen, the lumps or enlargement generally go away on their own over a period of months." ["Breast Lump"]. Your lumps are lasting a bit longer than usual, but it is still within the normal range.
What is happening is that your body is storing extra fat to fuel your growth when you hit your growth spurt. A prime area for fat storage is just under the nipples, but in developing the storage sometimes lumps appear and then gradually fade away. It does mean that you probably will go through a spell where your breasts will stick out for a while until the excess fat is used up. The condition is called "gynecomastia." It is temporary and fairly common among teenage boys.
Instead of just of bulging breasts because of excess fat, some boys also find their nipples getting larger. Both conditions are called gynecomastia, but this latter one is due to hormone problems. See: I have huge poked out nipples. Will they go away?
Also, the nipples in adults are more sensitive to touch than in a child. Extra nerve endings are developing and I guess you can say they are grouchy about waking up. Every little touch, even of clothing, or bump sets off the nerves. This too will calm down as your body gets used to the new sensations.