I had no idea things had been so bad, I knew he was being spiteful and hurtful to you, but all this indicates that he is cruel and manipulative. He sounds terribly like my ex so I can really understand what you are going through. Men like this are experts at blaming all their problems on other people, finding their own strength by bullying others, tormenting them. They are the type who would have pulled the wings off insects when they were little boys. Now he is doing it to you.
I spent years of my life trying to be fair to my ex, trying to encourage him to be a good father even though he had been a terrible partner, hoping that he would have qualities for my children that he hadn't found for me.
At the end of the day he was no different to the children, a nasty bullying person is a nasty bullying person. When you told us a couple of weeks ago what he said to you when you told him you were on ADs that did it for me. He really revealed himself with those remarks.
You have spent so long being controlled and bullied, in fact systematically broken down by this man that you now feel helpless to resist him - he beckons and you go running even though he has hurt you again and again.
If you can't challenge him with your emotions, then you have to get a firm grip mentally and let your head rule your heart. When your heart wants to give in to him, overrule it and do what you know is a favour to yourself. Continue to refuse to see him. He could see his kids if he wanted to, and after the way he has treated you you have every right to allow your father to mediate. If he truly wanted to see those kids he would arrange it with your father. He is using every situation to try and manipulate you and to make you feel like you are the one causing problems. You're not.
If he now doesn't see the kids that is no one's fault but his own. Stick to your guns. If he wants to go to court, let him. If the court hears all the evidence they will probably grant him contact but it will be laid out for certain times and days, and he will have to obey the court order or lose the right to see them. That would be much better for you, it would stop him from messing you about all the time.
How dare he say you are doing nothing! Looking after your kids is the most important job of the lot. I know you are studying too, and that is great, but make sure you are doing it because you want to and not because he has made you feel worthless.
Forestfly my friend. You have to hack this without a partner and recover from all the damage he has done for you before you go looking for another relationship. If you find a man now you will gravitate towards another one who will not treat you well. You need to expect more from someone to whom you are going to give everything. You need someone who is going to do the same for you. Do not entertain anything less for five minutes. Believe me, it will be better to be alone for ever than to have another man who bullies you. You have to get it into your head that you deserve someone kind, loving, someone who will return what you give in equal measure, or do not give them a thing of yourself. Your confidence has been crushed by this man, your needs have been ignored and you are now at the point where you think you don't matter. Never give another man the time of day until you find one who wants to take care of your needs. If you don't think you matter, no one else will.
Anytime you want to email me, go ahead. You have your parents and friends and all of us here on mumsnet who love you and want to help you heal. Don't ever consider going back to him even for one second. He is scum, and you are going to wash him off you and rebuild yourself.