No Connection with Mom
This person started their story by saying their bio-dad was super-cool. They knew about the OP from the beginning but felt that they’d have a better chance with a family who wanted kids. The bio-mom, however, is a totally different story.
The mom wound up having kids after the OP and kept them, which confused the OP. They knew the mom was in a bad place, though, so they thanked bio-mom for giving them up for adoption and having a better chance at life. Sadly, the bio-mom passed away due to drugs. In most cases, adoption is really the only way to give your children a fighting chance.