Please help me I have sole custody of my kids but now he wants joint custody but he dont even try to see them.?

I have given him so many chances to see them and he doesnt show up he doesnt even call them. My daughter made some allegations that he touched her so I reported it to dcfs im still waiting on that my kids are 9 and 10 and they are terrified of him and his girlfriend from past abuse that has happend to them by him. But now he is taking me to court to file joint custody even though we have been divorced almost a year. My children wont leave the house with him cause they are to scared I have tried to make them and I even have taken them to his house but they wont stay with him and wont let me leave what do I do I need help. I called my legal aide and he told me he is going to take care of it, but he said my kids cant testify on how they feel about it even in the judges chambers..I am lost and scared and I just want to keep my kids safe and this is killing their self esteem!