Your son wanted you more. He had to have you. Of course you never saw how un-healthy it was. I could have been the best Step-Dad in the world and the result would have been the same:
estranged (comparative more estranged, superlative most estranged). Having become a stranger, of one who formerly was close, as a relative, friend, lover, ...
He began pushing me away from the very beginning. And not just me, any lover of yours who showed interest, they were just smart enough to run when they saw what was coming. Your son didn’t want you to love me, marry me, grow old with me. He wants that. And what he wants he gets. Rich kids who get everything they want will settle for nothing less.