Wakeup's question about where it all went wrong is relevant. Part of moving forward is learning to recognise that it wasn't all good times and looking at the relationship with a more realistic view.
You say "the relationship started with lies which we never had for a year and a half of great relationship". This doesn't make sense at all. Can you explain further?
Generally speaking, relationships end for a reason. What was his reason for ending it?
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.