Why would i continue to believe a myth filled with lies and errors?. Because Jesus died for me? Well i cant be sure about that now since Genesis is false,
Two points.
One, Genesis is a myth, that does not tell an accurate story about the cration of the Universe and the Earth and life. This does not mean that it is false.
Second, yes, you can't be sure. Life is unsure. There's no guarantee that you will ever be sure. Get over it.