How can I get get a demo together?

I am an aspiring songwriter- I create lyrics and melody, but I don't play an instrument and I suck at making beats to go along with my songs. I can sing, not a Beyonce, more along the lines of Norah Jones. Anyway, I feel like my talent is being wasted because I don't play an instrument and therefore can't put a demo together. I was going to a so called producer, but he completely twisted my music into something he wanted rather than what I was trying to create. I feel so frustrated. I heard that in todays music world you have to submit a demo that is basically "professional" in order to even stand a chance. So my question is how can someone like me get a demo if I don't play an instrument and don't have music to accompany my songs? Please I need some guidance from someone with music industry experience or knowledge. Thanks for all advice!