Hang tough
The reason that victims often return to their abusers is because they know what to expect - it is a diseased level of comfort and familiarity. There is no need or use in beating your Self up for why you returned to him. The fact is that you (and, tens of thousands of others) did and it's over. There are many, many things that you can be grateful for: you did not enter into marriage with this man; you did not remain with this man for decades; you are bright and intelligent; you are well on your way to self-sufficiency. It could always be worse.
If it were me, I would defy the Court Order to allow him visitation with my son and the reason is simple: in order to see his son, that man will have to appeal to Family Court and be required to jump through many, many flaming hoops before he's allowed access to my son. I would be compiling every complaint, phone call (you can ask landline and cell companies for phone records up to 18 months past), and plea for help to build my case against him. The abuser will likely make lame, superficial attempts to appeal to the Court, but he won't involve himself in counseling, anger management therapy, or other requirements of the Court because of his arrogance and diseased state - he just won't do it.
Your war with this man will be a series of legal battles for nothing less than your emotional and physical safety and those of your son. Though you were involved in the legal mess for a year, it can often go on for many years when a victim finally leaves their abuser (male OR female), so be prepared, GET TOUGH, and harden your Self with resolve and righteous anger. You may need to move, change jobs, etc., but do so only after speaking with an attorney. If you do not have an attorney, yet, you can find one through many women's support groups (often, pro bono). In your State, you'll be able to search for women's coalitions and support groups that will be able to direct you to even better resources than you were aware of the first time around. Here are some other sites that you may find useful.
http://www.familysupport.org
http://www.abusesurvivors.meetup.com
http://www.gatehouseadultsupportnetwork.org
http://www.health.groups.yahoo.com
Again, my response has been long and I apologize. I encourage you to post, vent, rant, and express your Self in a healthy, productive manner. There are many, many Survivors of abuse that are willing to help you along your healing path. One word of warning is that some members may not respond with what would even be remotely termed as "supportive," but you'll be able to ignore that which is unhelpful to you in your process.
Best wishes, and do continue to post.