Hello and welcome to HealingWell and the Depression Forum. I believe that you will find lots of members that will listen to you here an advice you but please remember we are not professionals so our advice is from our own life experiences.
First of all my sincere sympathy at the loss of your Father. I am glad you were able to make amends with each other before his untimely death. Hold that close to your heart. That is a good thing.
I do not know what part of the country you are in but perhaps there are other agencies that could help you with programs for the children and getting you some relief from all your stress.
For right now, I think you need to take care of you and the new baby that is coming and not dwell on your Mother or anything else.
You have paid your dues for whatever wrong you did and you have nothing to be ashamed about so hold your head up high and take babysteps towards becoming more calm and centered.