Sorry things went so badly. Did you actually read the paper she had in hand, or did you just see a list of rules? If you did not see an official letter head from the lawyer's office....or his signature, then she may be trying to bluff you out. At any rate, she isn't going to play nice, so you best get to finding legal help ASAP.
I know you are down, but mothers are not just automatically handed over full custody of the children like they were years ago. Keep your chin up and fight for your kids. The Judge may be interested in knowing who wanted to end the M and why. I really don't know how much that weighs anymore, to be honest. It may depend on where you live, IDK. But I believe from what I read that most couples are having to share visitation 50-50.
Don't give up on who you are as a man and a father. You're not done! You are young and the future can hold blessings that you never dreamed of before.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!