[Coffee.]

Whenever you can, wear jeans or other clothing that can hide boners better, and just masturbate as you normally have. You also may want to come up with visual cues that can disgust you and help the boner go away when in public (think "grandma in the shower" or something ) There's nothing wrong with you. In your teenage years, frequent boners are common. But sometimes, the situations can be awkward, so just try your best to hide them if possible. And if not...it happens to everybody.