Well aware the OP cannot get married in the Catholic church if his first marriage is valid – which he says is it is. He is seeking to remarry “legally” which is not possible given what he has described. I am not contesting any of that (and my previous posts support this), just trying to explain to this other poster how her situation is different than his.
I don’t know exactly what he wants either – he states he wants a stepmother for his children, for a variety of reasons, but then admits he is validly married. He seems to want us to tell him that it is OK to get remarried if he is already validly married because of his admittedly tragic and unfortunate circumstance but of course no one can do that. It is obvious his Catholic faith is important to him, and he wants to remain observant Catholic, but there is no way around this besides an annulment, and he states he is validly married.