Random!!! Child custody

I know this is really off topic... But i have been sooooooo stressed.. My stepson is 8 almost 9. And his mother gave him a half dose of her zanaflex(muscle relaxer) AND an ADULT BENADRYL together to help him sleep.. My stepson has admitted this to his doctor, a social worker,to me and his dad and his therapist.. But guess what?? The judge almost gave custody back to his mom because my stepson said his dad yells at him. Which is true to an extent.... He gets upset because my stepson won't eat his dinner or he cries at the drop of a hat. He defends his mother like shes the perfect person which is expected. .. But we also alleged that she sells her prescribed medications out of her home... Which we have proof.. And nothing has been done.. Nothing at all. We have 50/50 custody. Oh! And she drinks while taking her prescribed pain killers... She got violent one night and told my stepson and his uncle to get the f*** up out of her home. And shes now done it again!!! Im so afraid shes going to get violent with my stepson and hurt him or od him on meds. How should we deal with this???? Noone will help at all!! We have no funds for an attorney.