You've handled it like a champ but I'm sorry you were with someone that made those choices. My thoughts are that you shouldn't allow your STBX's behavior post BD to alter the path you are on.
1) Do let go and accept your new life. Don't burn bridges or date others. There is a tendency to want to end limbo by doing that and justifying it with their WAS actions, but that wouldn't be true to YOUR character. Demonstrate in yourself the character you wished he had displayed.
2) Do continue to improve yourself and remain focused on your opportunities for growth that were uncovered in the M. Don't let yourself be fooled into thinking he was just a bad apple and its all on him. That would deprive you of a chance to improve for future Rs with him, someone else, or on your own.
3) Do set short term goals. Don't be overly controlling about how your life needs to look in 6-12 months if the actions you would have to take would burn bridges, etc.
All in all, only you know when you are truly ready to be done 100%. I think you're strong enough to accept that as a likely reality without contributing to that outcome by doing things to get it over with and feel better short term. Keep DBing in healthy, independent ways. You may feel like you're clinging, missing out, or devaluing yourself in the short term, but looking back you'll know you actually valid yourself too much to let his actions during a MLC or whatever derail you.
Those are my thoughts as I'm in a similar sitch, see my posts from a few weeks ago. I know you know this, wishin you strength, patience, and peace.
Ps- I was talking to my sister the other day about how I don't look at women the same. I told her I no longer find looks attractive, not bubbly personalities, etc. I said 'you want to see a picture of an attractive woman to me???' And I held up a woman's user names on these forums and explained that fighting and waiting for a marriage when all looked lost with patience and compassion was to me was more attractive than any dance hair cut or name brand jeans. Be proud to belong to that club and stay a member!
Me:38 XW:38 T:11 years M:8 years Kids: S14, D11, D7 BD/Move out day: 6/17/14, D final Dec 15