I'm sorry to hear about your situation. I'm in Oregon but you should do a google search for legal services in your area. We used to have legal aid here but they don't cover that kind of thing anymore. You could also represent yourself and go to court to explain what you need to. If your honest and a good father, try to get as many character witnesses as possible, friends, family (hers even better), but more than that, teachers, daycare providers, coaches and anyone else who has seen you interact with the kids. Unless your unfit you will be awarded visitation and if she's unfit than maybe even custody. I know it's not as easy as it sounds but it's all I have. Good luck to you children really need both parents in their lives if possible. God Bless.
To get a federal law passed, it must be proposed by the House or Senate and signed by the President (or vetoed, and the veto overridden).
Therefore, the only way to get into the system would be by contacting your state's Senator or Representative in Congress. Make sure you have good notes on what you want to accomplish and how it will be done.
State laws need to go through your state's congress (or some states allow laws to be placed on the ballot). The best way to do this would be to contact your local senator or representative and speak with them about what you want. Again, have good notes on what you want to accomplish and how to do it.
State representatives are generally more approachable, so I would start there (on the local level) and try to drum up support.
Good luck in your endeavors.