How do I tell my children we're not going to visit their Dad anymore? I can not afford it on my own & no longer together plus I said no contact cause I was so hurt& mad. I blocked him on email.

that is tough stuff... even though it is hard and you are med you have to make an attempt to NOT say negative things about their dad to them. you can explain the cost and how it isn't possible to visit, but you can encourage them to write him and keep connected (if they want to). Try not to be the reason they have mad thoughts about him so maybe they can have a relationship with him when he is released.