So he has you at his beck and call when it suits him and he's free to date whomever he wants? Wow, he won the lottery didn't he? There is zero incentive for him to change. He knows he's got you under his thumb and there are no consequences for him for dating while married. Maybe you should start dating instead of sitting around the house waiting for him to call. It's been 3 years. If he still loves you then you dating someone else will do the trick.
He'll want what he can't have. All people do. It's human nature. You're making it way too easy for him. You're a guarantee. Stop being a guarantee today. Have some self-respect. It'll work, I promise.
