Hey, lmg ~ busy month, so I'm just catching up. I've changed my display name and removed the detail from my signature but it's still me, Ingrid.
Of course you've had times when you feel horrible and sob. That's a normal reaction to learning that the solid ground you thought you were standing on all these years is actually quicksand. The man you were married to does seem to be gone and you're mourning as you would a death.
Your H did love you in those years. What he's going through now doesn't have much to do with you, it's his own journey. It's so easy to blame your partner for everything that's wrong, because then you don't have to take responsibility for the hard work of getting to know yourself, warts and all, and actually touching the wounded areas you've been avoiding.
It sounds as though the reality of the whole thing is sinking in for your girls too, and maybe even your H. One of the DB counsellors warned me that my H would probably seem to be very happy with his decision to leave. He's still here, so I haven't tested that theory, but it seems to be a common reaction, at least until the actual grind of living separately sets in.
You matter, just because you are alive and you are a human being, whether you are married or not. You will get through this and come out stronger, and it's possible that your M will be a better one in the end, too.