Is the Cross a Pagan Symbol?

I don't believe I came to genuine faith until I was around 17. But as a child, I am going through this book and all of the sudden is going through the whole story of Jesus and I'm identifying it because I grew up in a Christian household. And I get to the moment of the cross when Jesus was crucified and like, wait a minute, Jesus isn't on a cross. He's on a, he's on a steak and I just felt this inclination as a child and my stomach turned into nuts. So now that I've had some time to think about it, I even know where it's from. The cross is actually something that's taught as a pagan