I had trouble with that too. Teen Witch by Silver Ravenwolf really helped me. I don't know how old you are, but it really helped me. I grew up Methodist and my parents are very religious it was hard for me to separate myself from my family. But in the end I found out that I am the only one that matters in this quest for spirituality. Everyone else can believe what they want to. It honestly just takes a while. Do your research on both religions and see where you end up. I chose paganism because it just made more sense to me, silly as that sounds. It came naturally to me.
I really love Silver Ravenwolf's description of God.
I see God as a big, beautiful diamond with many facets. Each facet of God manifests as a positive religious belief. Witches see themselves as one of those facets on that diamond. Christianity, Judaism, Islam and hundreds of other positive religions make up that diamond too. Together we are all one.
It might help you understand that you aren't necessarily turning yourself away from God but seeing Him as more than the Trinity. Even the bible says God is infinite, so why does He have to be confined to just Christianity. Why can't God be male and female? Why can't Allah be the same as YHVH? Isn’t it just a name?