hey native, our stories are slightly similar (one carrying the M and doing it all, S couldnt' care less, exS with a significant other not caring how it affects kid/s)
Anyways, to answer your question, how to move on...right now things are still pretty fresh, the D just went through and there is , understandably, anger and frustration on your part, it's a feeling I had to fight with a lot as I drove myself mad trying to rehash the past in my head and trying to have it all make sense. It's an excersize in futility, I suggest you push the forward button in your brain and avoid such torture.
When those thought come,and come they will, quickly remind yourself that those were painful times, but that you are in a new path and will/deserve a new happy life.
How to treat her? well, the best advice I got was from a parenting book called "The Co-Parenting Survival Guide: Letting Go of Conflict after a Difficult Divorce by Elizabeth Thayer " It was a lifesaver during the times I seethed in anger as we decided when he'd have my kids overnight, how to deal with him, etc etc. The thing I remember the most was about thinking about the coparenting with your ex as a business transaction. The business being your daughter, you want her to thrive and do great, so you compromise accordingly, you treat the other person courteoulsly and business-like keeping feelings at bay.
It seemes hard now but trust me, it works. Mainly, work on forgiveness, as long as your hurt keeps bringing up what was or how she hurt you/family you will be unable to heal, or heal properly without deep wounds. My prayers your way, I know you will do just fine, you sound like you've learned lots from what has happened, something we can't say about our exSs who have jumped into a new R thinking "this time" it will really be all roses/perfect.
Be not afraid...I will repay you for the years the locusts have eaten Joel2
30something 2kids survivor of S, MLC, A, D I have peace in my heart, at last.
