Hopeless romantic? or hopeless at all?

I was just watching a movie and they said that distance can fire up the heat of the lovers, or it can cold up the fire until lovers forget themselves. Few minutes later, they said that a coward heart will never conquer the object of its love.
Mmmmm... and don't think I was watching a romantic movie, it was Disney's Robin Hood. Yes, the one with the fox and the bear. Too much wisdom for a children movie? Maybe not. If we teach children to fight for their dreams and loves since they are kids, it will be easier for them to develop in a competitive world.
I wish someone would have taught me to be a strong fighter. I've learned it on my way, but, still, I get frozen when it comes to build a relationship with someone I love. But, well, I'm speaking of building out something when I don't even try to get there.
I hear it very often and I tell it to others, and to myself, a lot: try, just try. Most of the times I don't even try. And then I regret it, over and over.
And because I feel I can't get somebody, I move on and fall in love with another guy. Same story, different moments, but the same end. Again and again and again... The worst is that, recently, whenever I feel there can be a possibility to build a serious, strong relation with someone I like, I get so frightened that I just run away... Yeah, not literally like Julia Roberts in Runaway bride, but I begin doing stuff to make that guy scare and get away.
The sad thing is that it works. They go. And then the time comes for me to stand in front of the mirror and look a lonely, scared but full of love woman. How long will I go on like this?
What it takes to change your destiny? What it takes to have the guts to change it? What it takes to be stronger?
Maybe I should begin by viewing it in my future. If you ask me where do I see myself in five years, I will tell you that I see me with a family. But if you ask me where do I see myself in 15, 20 or 30 years, the truth is I don't see me with a family... not even with a couple.
I think of me as somebody that, by then, would have raised one or two kids, and therefore I will be able to follow my own dreams to help people within my country, or maybe in some other places. And I think, in order to achieve that, it would be better for me to stay single, 'cause I won't be able to do it if I have kids to take care or a husband who will need me.
So, the real question now is... what is it I really want? Is it possible to have both of my dreams come true?