Best friends or nothing or more?

So, there's thig guy. Been best friends for three years. For three years I had him friendzoned, and he had a CRAZY ex but wanted me. Long story short, one day I was facing graduation and I finally grew up, This guy is what I want, for the rest of my life if possible. Problem? He has self-esteem issues and is in a committed relationship with another girl who based on observations from his behavior I'm convinced is happy with her b/c he's in wonder that a girl likes HIM. He knows how I feel and has since just after he first got with her, been with her for a year and I wonder am I done for now?

placeholder text for bug in Chrome