I'm proud of you...you handled it better than I would've had I been you, honestly.

You're right...David is acting INCREDIBLY childish, and he should be absolutely ashamed of himself. You're right in saying he's mad that you're doing well, and I would tell you good for you. The best form of revenge truly is living well.

Personally, were it me in your shoes, if he ever pulled any crap like this again, I'd casually toss out the word "harassment." Perhaps that'll cause him to grow up a bit.

Forgive me if that comes off as harsh of me, but I find myself angry on your behalf. :/

It's not at all a bad thing you're trying to move on. I like the fact you were able to explain and address potential criticism for "moving on too soon." To me, I think being cognitive of it and having a valid rationalization shows you're ready.

Keep living well, and leave David firmly were he belongs: in the past.