Step kids with abandonment issues

My poor 3 sweet step kids have been through it. And it's not fair. Their mother has issues and neglected them in the womb and after birth, ultimately completely abandoning them, causing FAE, ADHD, Mood Disorder, Learning Disabilities and of course, abandonment issues. I have four kids of my own that are seriously over being overshadowed by my step kids persistent need for attention. Besides counseling (which we already are doing) what other ideas are out there to help all the kids feel important and loved all the time!?! Sometimes I feel there's just not enough hours in the day. :(

I went from being an awesome mom, to feeling like an awful mom within 3 years. My older kids have even dropped the "We want to live with dad" threat and that breaks my heart into 1000 tiny pieces.