Possibly stopping breastfeeding due to medical issue...

Hey there, so I have Epilepsy and my neurologist is putting me back on my old medicine which is Depakote which has been known to cause birth defects if u take it while pregnant... Everyone I've asked has said there aren't any studies on taking it and breastfeeding and I'd hate to take that chance and something happen to my baby boy... Any advice on what formula to put him on, right now he takes formula as supplementation...also if I do decide to stop breastfeeding how do I deal with the engorgement of my breasts because when they're really full they hurt a lot :(