Reading your post, it seems you already know what you should do. It's hard, but if you stay with him, your life will only become worse.
If you let go of him, you will begin to feel so much better. It's the transition that is the hardest.
Let go or be dragged. If you already do not feel in love with this man, that's all you need to know. You have such a bright future ahead of you. He will only bring you down.