Sometimes you have to take karma in your own hands. He can't just break your heart and then expect you to help him. Just cut contact, he seems like a negative person to have in your life. Do what's best for YOU, don't hurt yourself in order to please him.
If that is how you feel, then what you should do is just simply and politely decline to offer any advice at all.
Tell them:
"In the years since you left me, I do not know the person that you have now grown to become. I cannot in good faith offer advice under those circumstances, but good luck."
Tell them:
"In the years since you left me, I do not know the person that you have now grown to become. I cannot in good faith offer advice under those circumstances, but good luck."