Please I need advice...?

Since I was a child, I never wanted to be a girl. In fact for many years, I thought that I could choose to grow up to be a man. As time went on I guess I realized I was a female and that's just how life would be. However, throughout my preteen and teenage years, I never stopped imagining my life as a male. I couldn't stand being female. I didn't really tell my friends, or anyone. I thought that my feelings would change if I got a boyfriend, which I did when I entered high school. I eventually found out about people who were living their lives as the opposite gender they were born as. I considered this, but I knew it would be devastating to my family. Although I wasn't content with the relationship with my boyfriend ( I felt I wouldn't be content with any relationship if I were female), I have continued to stay with him to this day, to try to ignore my feelings. I did once or twice express my feelings to my boyfriend, but he always brushed it off as if it was just me having weird thoughts. Now I am a senior in college. There has not been one day that I don't feel miserable over what I am. Every night I take a walk to think things over and consider what I want. If I didn't do this, I don't think I could endure another day. I finally decided to stay as I am to please those around me. However, since I've made this decision, I feel even more depressed. I feel like my mind and body don't match up and I'd rather just die than keep living like this. This is miserable and I feel selfish for wanting to be a male. I feel like a horrible child to my parents, I feel like a horrible sibling, and a horrible friend, even though none of them know. So, this is selfish of me, right? To want this? I should push through and be happy for them, right?