@PlayNice that sounds like a terrible childhood and I really empathise with you. I didn't have it nearly as bad as you, but I have a mother who is either NPD or Borderline (has never been diagnosed), and wasn't really there for us as a mother when my sister and I were growing up.
She didn't notice when I was getting so badly bullied at school that I would come home bruised and bloody and was driven to the point of suicide at the age of 13. She left when I was 15 and had very little to do with us for the next 15 years. Then she decided she wanted to be in our lives and it hasn't been easy at all.
At times I yearn for a mother, and like @Trusty Chords says, it takes therapy and a willingness to let go of the desire for your Mum to be any different than she is. It sounds like you've done some work on yourself though if she is in your life now and behaving - your boundaries must be quite strong for her to know that you would follow through on not having the kids in her life, so that shows you've come a long way and she doesn't walk all over you.
Yep, I find it hard to find a card too, that isn't so soppy and talking about how wonderful having a Mum is, because that's not my experience.
Hi @Skyler another thread we have in common :-( I grieve too for the same reasons - not having a child and only having angel babies. The ache to be a mother is physical and Mother's Day is just like another massive slap in the face.
My DH lost his darling Mum who he loved to pieces and sounds like she would have been an amazing Mum and I'm so sorry I never got to meet her. So we always visit her grave on Mother's Day and put flowers down for her and for all the angel babies.
So @PlayNice you're definitely not the only one that wants to totally avoid this day and wish it wasn't so hard - we've got three massive reasons to want to hide on Sunday - but then the positives are that my sister is a beautiful mother, and I am a step-mother, so we will celebrate anyway for those lovely parts of it. Maybe focus on the fact that you're an awesome Mum and that is a gift in itself