If you really hate yourself then you really cannot be sane

 Why?

Because hating yourself is self destructive in the extreme.

It often results in harming yourself or others in extreme ways.

What can you do?

You change your behavior to help yourself and others.

You start by learning to like yourself and learning to like other people too.

It really doesn't matter which comes first but you either start to like yourself or start to like others

or you do both at once.

Otherwise it is likely you won't survive to 30 alive or sane.

This is just what I observe in people all over the world every day.

I made it to 73 so far so I'm very lucky indeed.

By God's Grace