I felt similarly, but that's not unique - about half of the original fellowship of AA was agnostic or atheist. I am so grateful that I was open-minded enough to seek help in the rooms even though there were things I didn't understand. I continued to ask questions, learned to look for the similarities rather than the differences and trusted in the process. As it has been said, the 12 step fellowships are spiritual, not religious. I found a way of life for me that I truly love, and I hope you might give it a chance too. I wouldn't want to miss it for anything in the world.
The chapter called "We Agnostics" might help you to understand what's meant by a Higher Power in the rooms:
We Agnostics - Chapter 4
All my best wishes to you on your journey.