I don't know the laws in your state, but I don't understand why you'd have to get a lawyer involved to go after child support.
You've given him plenty of time to show you he'll provide support on his own, and he's failed miserably. It shouldn't have to be on you to ask him for money. If I were in your shoes, I'd let the state go after him for child support, and if he decides to go underground - let him. You can't change him. He'll eventually have to account for his actions somehow, someway. It would put the burden off of you, and this power struggle and bitterness / resentment that just can't be healthy for any of you.
Sorry your ex is like this -- but it seems you have a gem now in your current boyfriend.
Best of luck to you in navigating through all this and creating a life of abundance and joy.