liking a girl

i've been friends with this girl for a couple years now. a few weeks ago i started feeling a little nervous and blushy when i was talking with her. i think i like her but theres probably no chance that she likes me. sure, i've got a nice face and good grades, but i'm loud and my laugh is ugly. i've been getting a little more concious near her, like trying to be a little more quiet and laugh prettier when shes nearby,,,, but i kind of feel hopeless. like she wouldnt ever like me back.
should i abandon my feelings for her or keep being hopeful and try to get closer to her? if i do so, how?