I’d say explore Christian truth before turning to the Koran. I also no longer attend church services (click on link to see an article in which I discuss this) because for the most part they no longer meet my spiritual needs. If you have the time and are interested, you can also check out this article and this other one penned by me.
I have written a book titled “In Jesus Name” to help guide seeking Christians to understanding of what it means to be and how to be a Christian. There is no discussion of attendance at church services as a prerequisite to becoming a Christian. The book is available for sale on Amazon.com or Createspace.com.
I understand where you are. But giving up on Christian truth is not necessarily the answer. I still am a Christian because I believe in Christian truth. I realize, however, that Christian organizations are failing to be what they need to be, hence my recuse from Church services. If I were to find a Church organization that I felt was trying to live up to what Church should be, I would opt back in for attendance at Church services.
I hope you will check out my book.