What do i do if the father of my child is unfit and dangers?

i have a parenting plan with my ex-boyfriend. he has partial custody of our 1 year old son. but he continues to send our son home to me after a two-night stay with severe diaper rashes, bruises, dirty. and often with an illness. my ex has a history of reckless driving, speeding and has been in a wreck. he has been told of our child's intolerance to lactose but continues to give him milk products. which causes our son to brake out in a rash with hives and diarrhea. i would like to know if theres anything that i can do within legal limits to limit his visitation as he is not repecting the parenting plan and is neglecting our son. i have a lawyer but have been told by him that there is nothing he can do, untill we have another court date. that has not been set. i am tired of my son coming home with diaper rashs and his blatant disregard for our son's medical issues and hygiene. what can i do to insist that he follows the parenting plan. to keep our son clean and healthy, or limit his time with our son such as insisting on no over nights visits?