Hey hun, I am so sorry I didn't get around to reading this until now, I missed that your mother passed and am sorry for your loss, no mother is perfect mine is far from it but they gave us life so it is sad when they pass. The complications that have come out of that sound extra shite and I am sorry that you have to deal with people that are not worth your time or thoughts.
I am sure you will spread your wings and fly with the remaining family in due course but don't discount how awesome you already are, you are an amazing mum and have your own special family.
P.S. If you do fly, come on out to Australia, we would love to meet you all :D