HATE HIM

I have been married for 17 years. Have three children aged 16,15, and 10. After 13 yrs of marriage I found out that husband had an allegation of rape. He did not tell me I found out from a letter from court. He was convicted and sentenced to six yrs in prison. I looked after my kids by myself.He promised me hes a changed man and apologised everyday for putting me through this. I accepted his apology for kids sake and even took kids to visit him in prison regularly. Soon after his release he started being secretive and taking kids away without my permission. I had seen a solicitor and after he received the letter he started to brain wash my children. Because he comes from a wealthy background he could afford to take kids on expensive tours and private education.The kids now say they want to live with him because he is more "fun". I have sacrificed 17 yrs to care for my kids. My solicitor is very slow legal aid.I want to know what I should do to get custody of my kids  

I am a responsible mother. I want to know that my kids are safe. I know all my children's friends and their activities. I have always told my children where I am going and also expect them to tell me where they are. Since  he has come he is also inciting my children to be secretive and not share information with me that they used to before.Can judge decide to give him the custody?

He changed mortgage after coming out of prison from £950 to £1500 monthly without telling me. Is that illegal and after divorce would I be liable to pay that mortgage?