It doesn't matter what sin you commit. It is the same if you lie, and if you murder.
To help you understand, here is a analogy.
A chain is held together by round pieces connected together. However, if even one of them broke, the chain would fall apart. It's the same with sin. If you lied or you murdered, it would still seperate you from God.
So confess you sins to God and you will be forgivin.