Coping with challenging kids

I've researched and sought answers of how to cope with my children during this awful marriage. The impact of this has been so negative that my children act out. They are constantly, crying, fighting, yelling, the older child  I believe has developed PICA. Which is a rare eating disorder in which odd items are eaten or injested in order to cope with other problems. Basically the older child eats toilet paper, paint chips from the walls, crayons, lead from pencils, and I'm at a lose to figure out what to do to help. I'm afraid of seeking professional help for fear the child may be labeled some sort of deviant, or something that severe. Additionally I fear my spouse's reaction if he finds out I took the child to any sort of psychiatric or psychological evaluation. The child talks constantly, I mean 24/7 it is absolutely irritating. Being in such a predicament makes it challenging to parent children with both physical and emotional challenges, when I myself simply just want to hide and run away from my misery. What can an unhappy person do to help their children find peace when so much turmoil consumes every aspect of their life? I myself am so unhappy I want to sit in a closet and hide all day. I don't interact with anyone besides my mother, father, and sister. I have no friends, and avoid interacting with others. Am I really surviving ? How do I really help my little ones cope in an unhappy home?