I would respond to his texts and calls and be kind when he's around, but being a friend w/him won't work. He is still lurking and hasn't let you go completely and him knowing that you are moving on....well...he's not happy about that. I echo Andrew's concerns...be careful.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
