You do deserve peace, first of all. I don't blame you at all and I commend you for putting up with his indiscretions for so long. Abuse or not, repeated infidelity such as he has done is going to wear on your ability to endure. Even with addicts of any sort there has to be a point where, if they are not willing to change, no one can help them. Put an unwiling drug addict in rehab and it likely will not help and they'll return to the habit as soon as it's over. Him being aware of his issues are all well and good but as I've said to someone earlier today, "the road to hell is paved with good intentions" and whether you believe in a real "hell" or just figuratively, the saying still rings true. If he's aware of his issues and does nothing, nothing will change. You can't do anything to make him change. After 10 years of this I think you've done plenty to give him chances to fix things, which by the way, I'm sure you already know, you can't do for him.

I think that your thinking is straight on this and even if it were turning your back on him, I don't know if that's so bad, he has turned his back on you for a long time, by ignoring your wishes and pursuing his "highs"