I have had the opportunity to hear many of the responses from this post through my husband, who visits this forum site daily so I don't need to really dive into all the details of the matter. I would just like to share something with you.
I was 18 years old and on a path of destruction when I met my husband. I grew up in a home that went from wholesome to broken pretty quickly, (my parents split when I was 9 and didn't end up divorcing until just over a year ago when I was 20). From there, of course my world had been turned upside down so when I set out into the world myself, it was a pretty rocky experience. However, God had a special surprise in store for me. Even though I felt like a spoiled child and didn't have a relationship with Him at the time, He had, in his perfect providence, brought my husband and I together.
At the ripe age of 19, I was a bride.
And I will tell you.. it wasn't encouraged. My mother had always talked about the kind of man she wanted for me; Strong, put together, intelligent, handsome, someone who could challenge me, dominant, etc. As soon as she met that very thing, (my husband), it's almost as if she had shut down. She immediately rejected him. I will not speak ill of her but it's almost as if she talked about these things but didn't think I would find it.
What I'm trying to say is, even though I had not received the blessing of my parent, as you seem to being struggling with, it's still worth it to be with the love of your life. God wants that for us. No where does He tell us that we should remain with our parents; He does, however refer to marriage many times. These are just 2 that come to mind when thinking of your situation. I'm sure they have been told many times but how many things in the bible haven't?
(Genesis 2:24) That is why a man leaves his father and mother and is united to his wife, and they become one flesh.
(Mark 10:7) For this reason a man will leave his father and mother and be united to his wife
I emphasize this point because I believe that you should go through with this marriage. It would be your greatest mistake to deny your future husband his rights to you. I know if I had listened to my family, I wouldn't be here, almost 3 years later and happier than I've ever been, with a man who serves Jesus and loves me with all his heart.