This whole relationship sounds kind of rushed, but I'd be hypocritical to criticise you on that score. I guess my main point here is to recommend that you recognise there would be a large element of infatuation rather than love at this stage. Yes, it can all feel amazing and wonderful but it's a bit too early to be making any plans for the future.
Anyway, as for the question you asked: If he runs from you when all is good, what will he do when things are bad?? I think this is the most nonsensical excuse for leaving I've ever heard
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.