Ahhh i dont know what to do!?

Ok so here's the deal. my friend just expressed some stronger feelings towards me. And like it's weird for me. i consider him a brother, part of my family i never had any suspicion of anything other than friendship. and i told him it could never go farther than brotherly/sisterly family love lol and i normally don't find any situation awkward but after this i feel a bit weird. i just don't know what to do because i dont want it to be weird between us but after this, i don't think things will ever be the same? I don't even know what my question is but like idk if you have anything to say please tell me. anything that will help with this situation. I'm pretty shocked and surprised at the moment...this was totally out of the blue...