Is he seeing someone? If the answer is yes, don't bother trying to get him back. Respect him and his relationship.
Do you really think you've changed enough to permanently do better? Or are you just going to drag him along the rocks behind you while you try to get better and then just give up because you're tired of trying to change yourself for the better?
"Well, then," the Cat went on, "you see a dog growls when it's angry, and wags its tail when it's pleased. Now I growl when I'm pleased, and wag my tail when I'm angry. Therefore I'm mad."