I'm very sorry to read this. You haven't shared the circumstances so it's a little difficult to know quite how to pitch this answer. I doubt that much can be resolved via this forum except to suggest that loss of custody of children tends to mean that some aspect of your life or behavior is an issue?

If this is the case it perhaps points to the solution in that you may have it within your gift to alter the circumstances that led to this and thus be in a stronger positition to negotiate for greater access to your children. This is all wild speculation on my part.

If it's not too difficult, would you share a little more about the circumstances that have led up to this unfortunate situation?