I love my brother romantically

It all started when we were 12... We used to sleep in the same bed because our father was raising us alone and was in a difficult financial situation. So during the night I always crawled close to him into his arms because the dark made me worried. And he used to kiss my forehead to calm me down when I was scared. But one night, he kissed me on the lips... I didn't think much of it, presuming maybe it was an accident. But then he continued to do it, and each time felt more passionate...

Then years passed we formed a very special and intimate bond. We hold hands, kiss each other and he likes to rub my belly when we cuddle. I think we are romantically in love but I think it's wrong..I don't know what to do. It has felt fine this far, but I am having doubts.