Francis, if you look around the section of questions and answers you will find others who have asked exactly the same concern. Physical attraction, lust, sex (intercourse) and love are different element of human sexuality. These can be similar or different depending on the person. Many teens have fantasies and visual images while they masturbate of the same sex, this does not mean you are going to be gay. Your sexuality and all the underling elements are being developed and organized by your brain (brain-chemistry and hormones) during the pre-teenage and teenage ages.
Sexuality is fluid and can change during the course of a lifetime. However most people have a much clearer image of what they prefer sexually at adulthood. Discovering your sexual orientation is a whole process. Take your time, there’s no need to rush anything. Feelings and emotions are personal and only you can determine your true sexual identity.