Where did we go wrong?
That’s the first question we ask ourselves, and while it’s a valid one, it’s also one to answer promptly, honestly, and competently, and not to spend time wallowing in.
Of course you made mistakes — all humans do. Ask God to guide you in being aware of those mistakes, correct whatever is necessary, and move on. Prodigals happen in the best of families as well as in the worst, and you can find some measure of comfort in recognizing that the first Prodigal Son and Daughter were Adam and Eve.