In the same boat?

Here it is, late at night, and I am on the computer reading that a lot of people are in the same boat as me. I am so unhappy in my life and marriage. I have been married for 24 years to a person who everyone thinks is the best guy in the world. On the outside we look like a great couple but in private I am struggling bad. He has always put me last. Everything and everyone comes first. There is zero compassion and respect. Our whole marriage has been about him. We have discussed this many many times and he always promising to change and never does. I am totally drained from trying to stay in this marriage. He has never been with another woman or hit me. We have 3 grown children and he has been a great father to them all. He professes his love for me but still I remain at the bottom of the food chain and I am drained - spiritually, physically and emotionally. I feel the only solution is out.