Could m move out and try your local relationship before taking a big step? Transitioning from LDR to living together can be difficult in of itself, throw a blossoming romance into the mix just complicatestthings further.
If you were me I would have M move out, get the marriage annulled and just date him more casually and see if you can't get those old feelings back. I would continue seeing D on my terms.
Sue, hinge in a vee with Nate (Polysexual) and Sam (monogamous)