Stop putting yourself through pain. He is obviously happier without you now. You do not need to try anymore. Why try when you no longer have to cry over someone from the past. Dry your precious eyes because everything will be okay. He left, without a word or without any reason. He left you … to give you room. The room for others to treat you better. He left you with bittersweet memories and lessons learned. Breathe and let go.
Someday, if your paths cross, try to talk to him, try to figure out where you went wrong.
Stop wasting your time checking on him, it is not doing any good on you! Just let go. Though it hurts now and it will still hurt later, stay strong and stay positive!