The withdrawal from these drugs is a very ambiguous subject. No one knows how these drugs work exactly, so knowing how the withdrawals work would be an even harder task.
Speaking from experience, as I have withdrawn from gabapentin and pregabalin several times -- cannabis, benzodiazepines, a light opioid such as codeine, are things that can definitely help. If you're looking for supplements, I found magnesium to be a big help since it operates in a similar way that gabapentin is thought to. Gotu kola is another one that I found relieves a lot of the withdrawals.