If you care about your ex, leave him alone. He's grieving. Most likely when he encounters you its a couple steps backward for him. It sounds from the way you described it, he parented you. It's time to stand on your own 2 feet and give him a rest. This is not said to be cruel. He has enough on his plate. You have moved on. You could write an appreciative letter of apology. That might ease your guilt and put this matter to rest.