If you are in a custody battle then I know how worried you must feel. These are intense and worrying times, and for most parents, it will become a living nightmare. Having your personal life and your own history dredged up in court can feel embarrassing and distressing.
if you aim to get out of the court in one piece, though, I highly recommend you hire a child support lawyer. Someone like this can be very useful in building and preparing your case. The biggest challenge comes from making your argument for why you should have custody clear.
You also need to make sure your character shines through. A lawyer can ensure you can more readily make your case and build an argument that works in your favor.
Good luck, but please do not try and fight this case on your own: you have too much at stake.