You are correct, he won't change. Talk is cheap.

Saw this quote today..

'Codependency is driven by the agreement that I will work harder on your problem and your life than you do. This is not Love. '-unknown

Not sure if that applies to you? It's rather typical of abusive relationships. Reality is, statistically speaking, it takes well over a dozen times before a victim actually leaves. Some physical abuse, is still abuse.

Are you currently in counseling? It's a good start to help regain clarity.

They seem like best friends, don't they? Best friends don't strip a person's dignity, sense of self worth, make empty promises. And they certainly don't treat with malicious intent.

Once the roller coaster dynamics are in place, there's really no turning back.

What makes him the end all, be all to your existence?