serious stuff-what should i do ?

Here is my story.I am an 18 year old teen and I met a girl in college and I fell for her after being friends soon.I proposed her immediately and she also developed feelings for me. But, she fears for her future .She is scared that marriage is a tough situation ( I love her to marry ) and she is scared that what may happen in the future if we get committed and what would happen if misunderstanding develop and what would happen if families reject.
So taking all into consideration she said no to the proposal and she always asks me to be with her she shares everything with me .she asks me to be with her as a friend forever and also she misses my company if I leave her. She wants me to be with her forever but as a friend.she is scared to get committed even though she has feelings.. she was first kinda thinking even after rejecting but these days she is saying no.. Even though she has feelings I can see and feel it.. she is trying to erase jet feelings on me away... But.. I love her a lot..how to make her love me...

I go like a dog behind her everyday but we are best of friends.. One week I completely avoided her and she told her friend that she was falling but as soon as I startef talking like normal she started the same rejecting mood.

She gets pissed off when I talk about love on her..but she likes me.. And she is clearing herself to avoiding fall in love .she is scared to get committed.. How will I prove..and make her fall ?

Its becoming worse we have challenged that one day she will love ( my challenge ) and she said that she won't forever ( her challenge)
Even though she has feelings she is scared and is trying to clear things out...

How do I make her love me and prove myself.

She is lying to you. When girls make up a thousand excuses why they can't be romantically involved in you, it means they are avoiding telling you the truth....they don't feel love for you in that way. She sees you like a brother, not a lover. She keeps you around for the attention and nothing more. Stop following her around like a love sick puppy, and move on. It ain't gonna happen, ever.

Tip: when a girl makes up excuses, that means she is not interested, you are being rejected. Stop being friends with girls. Only ask girls out on dates you like, be friends with guys instead.

I agree with smackie. Also you cant make someone fall in love with you. You cant make her love you. It doesnt work like that. I know thats not what you wanted to hear, but its the unfortunate truth. Also I wouldnt go proposing so soon with women. Makes a guy seem needy. And weird.