Wow - he left three years ago, and you're STILL willing to give him three months to "decide"? You're a bigger woman than I am.
You DO deserve someone who cares about you. So don't spend this three months waiting around for him. (And make sure he's not doing any financial funny business during this time). Spend these three months living and enjoying life, and making plans for a fabulous new future. IF he turns around, you can decide if you want him then. But I get the feeling you've been holding your breath long enough - time now to breathe!