Sex before marriage

So this issue is annoying my guts and I wanna finalize it. I have a boyfriend that I love and I really wanna have sex with, however if my family ever knows they will never talk to me again.

My family is extremely, extremely religious (Muslims). I even went to a religious school when I was younger. We were taught what to believe in without explanation. Growing up and going to college abroad, I started questioning all my beliefs and honestly many of them do not make sense to me anymore. I have certain beliefs that my family will never accept, including the fact that it's OK to have sex before marriage. However, I love my family a lot. I don't know whether to follow what I want or what my family wants.

I have spend years of my life trying to please everyone around me and not me. I feel like my 20's are going in vein trying not to hurt anyone. I'm tired of that and I wanna do what I wanna do. But my family has been always my 1st especially mama and I don't wanna let her down. She sacrificed a lot for me.

What would you do if you were me?