Frigid onanoko not sure, but think you no have big problems. Must have been quite fun night both of you - great!
She only scared of, maybe, difference in longterm relation you gonna have now. What to tell best platonic friend? truth. You liked that night, and you wanna communicate that. and you wanna talk about the rest.
She invite you to somewhere. So she not cut you off, and wanna be with you still. After beer, invite to your place again. See what happens. Frigid onanoko think you no longer 'platonic.'
say goodbye now.