Trouble with ex spouse

I have been divorced almost a year and have joint custody of my kids, and I’m finding out a lot not only from my children but adults as well that my children are being told to lie (I caught him telling my child to lie to me about something stupid on the phone) and being told lies by their father and his girlfriend about me. I don’t have an attorney anymore because I can’t afford one. Anyway, I found out my kids were told I informed my ex husband’s job he was on drugs (which I did not) and that I supposedly harass him and his girlfriend. My children have told me about being hit for fun by said woman and also mentally/emotionally abused by this person and their father does nothing but take her side. The schools have called DHS along with other parents and my children have to tell DHS everything is fine at their dad’s house. My kids have come to my house with marks, which I turned into my divorce lawyer who said it was nothing(she no longer represents me), they act scared to be alone, they never wanna go back to their dad’s but I don’t have a choice about taking them back. Not to mention I’m always threatened with being put in jail and so are my kids. Something was done to my daughter and my son and turned into DHS/DCFS and their father and his girlfriend said they will go to juvie/jail for lying. I saw what happened to my daughter so I know she didn’t lie and my son wouldn’t lie about what happened to him. Oh and one of my kids did inform a DHS case worker he/she was told to lie to them and the case was still closed and not really looked into. There’s a lot more but this is already really long. How am I supposed to help my kids if I can’t afford a lawyer and legal aid won’t help and nobody will really look into what’s going on in that house?