What should i do?? please help?

i have known this girl for a year nd we like talk everyday all day bout everything. We ar proper close and reeli reli good mates. i told her about 5 months ago that i liked a girl but about a month ago she told methat she loved me(she is straight) but i just dissmed the fact but i loved her bak i told her about a week later then she didn't now. We talked about it then we kept leavin it then comin bak to it. then i told her i wantd to be more that bestmates she sed so do i but i dow wannaruin anything n i dow now wats best. Ho do i let her now it is bst to be mre. Thanks xx